A visitor guide to volcanoes in New Zealand

New Zealand is a land of outstanding natural beauty, with a diverse landscape that ranges from sun-kissed beaches to snow-covered mountains. But what really sets this country apart is its volcanic activity. Our location on the western rim of the Pacific “Ring of Fire” means that earthquakes and volcanoes are a daily part of life in New Zealand.

Whether you’re a geology enthusiast, a thrill-seeker, or simply someone who wants to experience the awe-inspiring power of nature, a visit to one of our many volcanoes should be high on your list of must-do activities. No doubt you have questions like “How active are New Zealand’s volcanoes?” and “Is it even safe to visit an active volcano?” and in this comprehensive guide we’ll answer those questions and many more.

We’ll also explain the different types of volcanoes found in New Zealand, from composite cones to calderas and we’ll touch on the fascinating science of volcanic eruptions, as well as cover the important distinction between active, dormant, and extinct volcanoes.

Finally, we’ll take you on a brief tour of some of the most interesting volcanic sites in New Zealand, including recently active Whaakari/White Island, and we’ll also showcase other active volcanoes such as Mount Ruapehu and Mount Tongariro.

So whether you’re looking for a scenic hike on an active volcano, or just want to appreciate our volcanoes from afar, this guide has everything you need to know about visiting volcanoes in New Zealand.

Why does New Zealand have so many volcanoes?

New Zealand is located on the western rim of the Pacific “Ring of Fire”. Viewed from space, this roughly horseshoe-shaped belt borders the Pacific Ocean and marks the boundary between tectonic plates. In the case of New Zealand, we sit on the boundary between the Pacific Plate to the east and the Australian Plate to the west.

Tectonic boundaries are highly active areas due to the interaction between these plates. As the plates move, they interact in various ways, such as subduction, where one plate is forced beneath the other, causing the melting of rocks to form magma. This process can lead to the formation of magma chambers, which can fuel volcanic eruptions as the magma finds its way to the surface through weaknesses in the earth’s crust.

So New Zealand is essentially ‘living on the edge’, made even more interesting by the fact that in the north, the Pacific Plate is diving below the Australian Plate to form a highly active volcanic zone while in the south, this interaction is reversed to form the Southern Alps mountain range. It’s little wonder then that New Zealand is such a volcanic hotspot.

Types of volcanoes in New Zealand

There are several types of volcanoes that can be found around the world, each with their own distinct characteristics and eruption styles and in New Zealand we have examples of most of them. So for example, Mount Nguaruhoe is a composite cone whereas Mount Tarawera is a lava dome.

To help you understand what each of these terms means, here is a brief explanation of each type.

Shield volcanoes

These are broad, gently sloping volcanoes that from the side, take the shape of a warrior’s shield. They are generally the least explosive type of volcano, formed by repeated eruptions of relatively fluid basaltic lava. Examples in New Zealand include the extinct Banks Peninsula and Dunedin Harbour volcanoes.

Composite cones

Also known as stratovolcanoes, their shape is what we would typically associate with volcanoes since they are the most common type of volcano and are often very explosive. Composite cones are steep-sided and made up of composite layers of tephra (fragments of rock) or lava deposited over the course of many eruptions. The most iconic examples in New Zealand are Mount Ngauruhoe and Mount Taranaki.

Lava domes

When sticky, silica-rich magma rises slowly in a volcanic vent, instead of exploding, the magma can pile up on itself to form a steep-sided mound called a lava dome. There are more than 150 lava domes in the Taupō Volcanic Zone and of those, Mount Tarawera is the most well-known.

Calderas

Very explosive volcanoes can eject a huge amount of material and then collapse into the emptied magma chamber below to form a basin-shaped depression called a caldera. Calderas can be several kilometers in diameter and are often filled with water, forming a crater lake. The largest example in New Zealand is Lake Taupō which also happens to be a supervolcano. More on that later.

Active versus dormant versus extinct volcanoes in New Zealand

In this guide we’ll make reference to active, dormant and extinct volcanoes, so it’s worth explaining what we mean by these terms.

Active volcanoes

When we think of ‘active’ volcanoes, we typically think of flowing lava and billowing clouds of ash but that isn’t necessarily the case. In general, an active volcano is one that is currently erupting or has erupted recently. The term ‘recently’ is where things become a little murky as there are varying definitions of recent.

For the purposes of this guide, we’re going to rely on GeoNet which operates New Zealand’s geological hazard monitoring system and officially monitors 12 volcanoes in New Zealand. It’s worth mentioning that most of these 12 have not shown any significant activity for thousands of years.

We have however chosen to classify 5 of the 12 volcanoes as recently active, with Whaakari/White Island being the most recent New Zealand volcano eruption, having last erupted in December 2019.

Dormant volcanoes

A dormant volcano, sometimes referred to as a sleeping volcano, is one that’s not currently erupting or showing any signs of volcanic unrest such as earthquakes, ground uplift or subsidence or the presence of volcanic gases. Dormant volcanoes are often characterised by a long period of inactivity, typically spanning at least a few thousand years. Dormant volcanoes can in theory erupt again in future.

Extinct volcanoes

An extinct volcano is one that’s no longer capable of erupting and has remained inactive for a long period, typically tens of thousands to hundreds of thousands of years. While the classification of a volcano as extinct can be somewhat subjective, it’s generally accepted that these volcanoes are not expected to erupt again in the future.

Volcanic eruptions

While you never want to experience a volcanic eruption first hand, you may be interested to know a little more about eruptions and more specifically, what you might face if you did find yourself in the wrong place at the wrong time.

Lava

Magma is created by the melting of rocks deep inside the earth. Depending on the type of rock (such as basalt or rhyolite) and the proportion of various chemical compounds, in particular Silicon Dioxide, magma will have different characteristics. It could be runny and effusive (non-explosive) or sticky and explosive or anywhere in-between.

When magma reaches the surface it’s called lava and based on the magma type, it could flow gently downhill or it could be ejected violently into the air and fall to the ground as molten spatter or even lava blocks and bombs.

Pyroclastic Density Currents (PDCs)

In volcano disaster movies where the heroes are desperately trying to outrun a massive boiling cloud that’s bearing down on them, that’s called a pyroclastic density current or pyroclastic flow. These are formed when the eruption column of ash and other material above the volcano collapses and surges down the slopes of the volcano.

The good news is that not all volcanoes form pyroclastic flows. The bad news is that if you’re close to a volcano when a PDC forms, you’re chances of survival are not great. PDCs can travel at speeds of 50 to 100 km/h (30 to 60 mph) and in the case of the most recent eruption of Taupō (232 AD), it’s estimated that the PDC travelled at up to 700 km/h (435 mph)!

Lahars

Lahar is an Indonesian term for a volcanic mudflow that can occur during or after a volcanic eruption. Ash and other volcanic material combines with water to form a slurry that can flow rapidly down the slopes of a volcano, carrying with it large boulders, trees, and other debris.

Lahars can form as a result of heavy rainfall, melting snow and ice or even the collapse of a natural dam wall, as was the case in the 1953 Tangiwai Disaster on the slopes of Mount Ruapehu.

Volcanic ash

Finer particles in the eruption plume of a volcano can rise several kilometres into the air and then, carried by the wind, fall back to earth over a large area. Fine particles in the ash can irritate the lungs and cause breathing difficulties, particularly in people with pre-existing respiratory conditions. The ash can also cause irritation to the eyes and skin.

How safe are New Zealand’s volcanoes?

Having explained the deadly characteristics of an eruption, now’s probably a good time to talk about safety. The first thing we need to point out is that there are no guarantees when it comes to volcanoes, active or otherwise. Consider this to be our disclaimer.

Unexpected, or blue-sky eruptions have happened in the past and could happen again in the future and our best defence against future events is careful monitoring and risk assessment based on past events.

Volcano monitoring and alert levels

GNS science in collaboration with Toka Tū Ake EQC runs GeoNet, which operates New Zealand’s geological hazard monitoring system. GeoNet monitors natural hazards including landslides, tsunamis, earthquakes and volcanoes and they do this using a number of different tools.

In the case of volcanoes, these include cameras, seismic drums and the analysis of gases and ground and lake water. They use all of the data gathered to assign an alert level to each of New Zealand’s monitored volcanoes, on a scale of 0 to 5 where 0 means no volcanic unrest and 5 is a major volcanic eruption.

Obviously, the best way to stay safe is to avoid volcanoes entirely, but since they’re one of our major attractions we can’t exactly expect you to do that. But some common sense will go a long way towards staying safe.

GeoNet publishes alert level information on their website so it’s always a good idea to check the current alert level before visiting any of our monitored volcanoes. In addition, most of our more active volcanoes are within our National Parks which are managed by the Department of Conservation (DOC).

So in the case of Mt Ngauruhoe, Mt Tongariro and Mt Ruapehu which sit within the Tongariro National Park, you should always check in with the local DOC visitor centre before heading out as they will be able to advise you based on the current alert level.

And if you choose to go on a guided activity such as the Tongariro Crossing, a certified guiding company should be aware of any raised alert levels and will respond accordingly.

What to do in an eruption

So let’s say, despite your best efforts, you’re caught in an eruption while out hiking, as was the case in November 2012 when the Te Maari Crater on Tongariro erupted. What should you do?

1. Don’t panic! Easier said than done but the last thing you want to do is to start running around in a panic and potentially risk injuring yourself by running off a cliff. Obviously you want to move away from the direction of the eruption as quickly as possible but at the same time you want to keep a close eye on the event itself. Conditions can change quickly and a seemingly harmless plume of ash can quickly change to a full-blown eruption spewing massive lava blocks and bombs.
2. Don’t assume that you’re far enough away. In the case of Te Maari, a few months prior to the November eruption, there’d been a far bigger eruption that ejected massive blocks, the largest weighing 3 tonnes, which covered an area up to 2.2km (1.4 miles) from the crater itself.
3. If you’re in a low-lying area, particularly in a valley or close to a river or stream, move to higher ground as quickly as possible to avoid the risk of a lahar.
4. Try to avoid any ashfall if at all possible, and if you are caught in an ash cloud, cover your nose and mouth to protect your lungs.

Apart from the above, all of the usual outdoor emergency principles apply in terms of staying safe, dealing with any injuries and alerting emergency services if required.

So on that cheery note, let’s now take a closer look at where New Zealand’s volcanoes can be found.

New Zealand’s volcanic zones and fields

Apart from the Kermadec Islands which are approximately 860 km (534 miles) to the north east of New Zealand, all of our monitored volcanoes are on the North Island or just offshore, with our most active volcanoes located in the Taupō Volcanic Zone.

Taupō Volcanic Zone

The Taupō Volcanic Zone is a 40km (25 mile) wide and 240 km (149 mile) long region in the central North Island that extends from Mount Ruapehu in the south to Whakaari/White Island to the north.

Formed in the last two millions years by the subduction of the Pacific Plate beneath the Australian Plate, this rift valley or graben is expanding by around 12-20mm a year. As the crust has twisted and thinned, magma generated below the zone has led to increased volcanic and geothermal activity.

Auckland Volcanic Field

So here’s a fun fact, the city of Auckland, which is where you’re most likely to arrive as a visitor to New Zealand, sits within the Auckland Volcanic Field. Made up of 53 recognised volcanic cones and craters, this field was active from around 193,000 years ago with the most recent eruption approximately 600 years ago.

Unlike the volcanoes in the Taupō Volcanic Zone, Auckland’s volcanoes were formed as a result of intraplate volcanism thanks to an active hot spot of magma located approximately 100 kilometres beneath the city.

Despite being dormant for hundreds of years, the Auckland Volcanic Field is still considered to be an active volcanic field, with the potential for future volcanic activity. But don’t worry, this field is monitored by GeoNet and according to them, “an eruption in the Auckland Volcanic Field is a low probability event on human timescales but would have high consequences.” No kidding!

Coromandel Volcanic Zone

The now extinct Coromandel Volcanic Zone stretches from Great Barrier Island off the coast of Auckland, down through the Coromandel Peninsula to Tauranga and the southern Kaimai Ranges. This zone is considered to be a precursor to the Taupō Volcanic Zone.

Whangarei Volcanic Field

Similar to the Auckland Volcanic Field in that it was also formed over a hot-spot rather than on a plate boundary, the Whangarei Volcanic Field is much older than the Auckland field and was last active between 260,000 to 319,000 years ago.

One of the more prominent volcanic features in the area is Mount Manaia, the remnants of a 50 km2 (19 sq mi) stratovolcano that erupted around 16 to 22 million years ago.

So aren’t there any volcanoes on the South Island?

There are volcanoes and volcanic fields on the South Island but none of them have erupted for several million years. All that remains now are the eroded remnants of shield volcanoes that were last active around 8 to 20 million years ago. The most well-known and visible examples of these are the Dunedin and Banks Peninsula volcanoes.

A map of volcanoes in New Zealand

There are of course hundreds if not thousands of volcanoes in New Zealand in various states, the vast majority of which are not named or specifically identified. Trying to show all of these volcanoes on a map would be fairly pointless so, since this article is part of our New Zealand travel guide series, we’ve focussed on volcanoes that as a visitor, you would be most interested to know about.

Recently active volcanoes

The map above shows all 12 of the actively monitored volcanoes and volcanic regions in New Zealand. While some of these volcanoes have not shown any activity in thousands of years, a number of them have erupted in the last few decades or in some cases, the last few years. Here is an up-to-date list of active volcanoes in New Zealand:

• Mount Ruapehu: last erupted 25 September 2007
• Mount Tongariro: last erupted 21 November 2012
• Mount Ngauruhoe: last erupted 19 February 1975
• Whakaari/White Island: last erupted 9 December 2019
• Kermadec Islands: last erupted 17 March 2006

Mount Ruapehu

Location: Central North Island
Type: Stratovolcano
Last eruption: 25 September 2007

At 2,797m (9,177 feet), Mount Ruapehu is the highest mountain on the North Island. It marks the southern end of the Taupō Volcanic Zone and has been the most active volcano in the area for the past 35 years. Three summit craters have been active in the last 10,000 years. Two of them are now covered by ice and are no longer visible, but the southern crater is today filled by a crater lake.

The most recent explosive eruption in 2007 spread ash, rocks and water from the crater lake across the summit area and caused a major lahar. The lahar alarm-response system was triggered and as a result there was no loss of life or significant damage, unlike the tragic Tangiwai Disaster in 1953.

Visiting Mount Ruapehu

Mount Ruapehu is home to three ski fields (Whakapapa, Turoa and Tukino) as well as numerous popular walking tracks and hiking trails. As a result, the mountain is carefully monitored with an eruption detection system (EDS) and two lahar warning systems (ERLAWS & VLAWS) providing early warnings.

The majority of the time, Ruapehu sits at Level 1 (minor volcanic unrest, considered to be normal for Ruapehu) with a 700m (2,300 feet) exclusion zone around the summit crater lake. At alert Level 2, this zone is extended to 2km (1.24 miles), with increased risk of lahars in valleys and rivers that are known lahar paths.

While you can of course explore Mount Ruapehu independently, if you do want to explore beyond the upper limits of the ski fields, we strongly suggest going guided.

You can check the current alert level here: Ruapehu Volcanic Alert Level

Mount Tongariro

Location: Central North Island
Type: Stratovolcano
Last eruption: 21 November 2012

Mount Tongariro, or to be technically correct, the Tongariro Complex, consists of multiple volcanic cones that formed over a period of around 275,000 years. The most recent eruptions occurred at Te Maari craters in August and November 2012. Nobody was killed or injured in these eruptions although the outcome could have been a lot worse.

Rocks ejected from the crater destroyed a popular hut that was just over 1.5km (0.9 miles) away. Fortunately, nobody was staying in the hut at the time.

Visiting Mount Tongariro

Tongariro is home to the Tongariro Alpine Crossing which is one of New Zealand’s most popular day hikes and without a doubt, the best way to see the various volcanic features of the complex, including Red Crater, Emerald Lakes and Blue Lake. As with Ruapehu, you can do the crossing independently, but going guided is the safest option.

You can check the current alert level here: Tongariro Volcanic Alert Level

Mount Ngauruhoe

Location: Central North Island
Type: Stratovolcano
Last eruption: 19 February 1975

Although recognised as a volcano in its own right, Mt Ngauruhoe is technically the youngest cone (around 7,000 years old) of the larger Tongariro Complex. It’s considered to be the most continuously active of all the volcanoes in New Zealand in recorded history, with Māori having recording many eruptions prior to European colonisation.

The most recent eruptions in 1974 and 1975 were explosive eruptions of ash and lava blocks which were thrown as much as 3km away. A towering ash cloud was formed which then collapsed and avalanched down the sides of the mountain.

Visiting Mount Ngauruhoe

Mt Ngauruhoe is a prominent feature that dominates the skyline during the first few kilometres of the popular Tongariro Alpine Crossing walk. The track will actually take you through old lava flows on the slopes of the mountain, the most recent lava flow having been produced in 1954.

While it is possible to climb Mt Ngauruhoe, this is now strongly discouraged for both cultural and safety reasons.

You can check the current alert level here: Ngauruhoe Volcanic Alert Level

Whakaari/White Island

Location: Bay of Plenty Region
Type: Stratovolcano
Last eruption: 9 December 2019

Located approximately 50km (31 miles) off the Bay of Plenty coast, this island is the site of the most recent New Zealand volcano eruption. Built up by volcanic activity over the last 150,000 years, with its distinctive white plume what you can see is just the tip of a much larger volcano, most of which is below the sea.

Despite there having been eruptions in 2012-2013 and again in 2016, up until 2019 it was possible to go on walking tours of the island. Tragically, an explosive eruption took place at 2:11pm on Monday 9 December 2019, killing multiple visitors and guides, and injuring many more.

Visiting Whakaari/White Island

Given the events of 2019, it should come as no surprise that it is no longer possible to visit this volcano. Several years ago we were fortunate enough to be able to visit Whakaari ourselves and it was a truly unique experience. You can see photos and read about our visit here, Visiting Whakaari/White Island.

You can check the current alert level here: Whakaari/White Island Volcanic Alert Level

Taupō

Location: Central North Island
Type: Caldera
Last eruption: About 1,800 years ago

Taupō is a bit of an exception as far as our classification goes. It last erupted around 1,800 years ago which is obviously not recent but, as we write this, it is one of just three volcanoes in New Zealand with an alert level higher than 0 (currently 1). Taupō also happens to be our hometown which is why we have a particular interest in this volcano.

The Taupō eruption in around 232AD was one of the most violent eruptions in the world in the last 5,000 years, producing a pyroclastic flow that is believed to have travelled at up to 700 km/h (435 mph) destroying all vegetation within a radius of about 80km (50 miles).

But that was nothing compared to a previous eruption (the Orunanui eruption) around 27,000 years ago. This eruption is what gave Taupo its supervolcano status. A supervolcano is any eruption that produces more than 1,000 cubic kilometers (240 cubic miles) of ejected material.

In the case of Taupō, the Oruanui eruption produced around 1,170 cubic km. To put that into perspective, the 1980 eruption of Mt Saint Helens in the US produced just 1 cubic km.

Visiting Taupō

Taupō is New Zealand’s best example of a caldera volcano which is now filled by New Zealand’s largest lake, Lake Taupō. Yes we get regular earthquakes which can be a little disconcerting. We even had a small tsunami on the lake in December 2022 after a magnitude 5.7 quake. But don’t let that put you off visiting this amazing little lakeside town.

There’s lots to see and do in Taupō, and it’s a great place to base yourself if you want to explore more of the central North Island. To find out more, check out our detailed guide, Top things to do in Lake Taupō

You can check the current alert level here: Taupō Volcanic Alert Level

Kermadec Islands

Location: The Kermadec Island Chain
Type: Stratovolcano
Last eruption: 17 March 2006

Located around 860km north east of New Zealand, The Kermadec Islands are the summits of large volcanoes raised by the ongoing collision of the Pacific and Australian tectonic plates. The largest of these mounts is Raoul Island which was the location of the chain’s most recent eruption in March 2006. It’s believed that a localised earthquake swarm caused the large magma chamber below the island to erupt.

The island is uninhabited although tragically, a Department of Conservation employee was killed by this eruption.

You can check the current alert level here: Kermadec Islands Volcanic Alert Level

Dormant volcanoes

Although considered dormant and therefore unlikely to erupt any time soon, the volcanoes in this category are all monitored by GeoNet and are assigned an alert level. At the time of writing, all of these volcanoes are at alert level 0, No volcanic unrest.

Rotorua

Location: Central North Island
Type: Caldera
Last eruption: Less than 25,000 years ago

Formed around 220,000 years ago, Rotorua is another lake-filled caldera and the lakeside town of Rotorua is a popular tourist destination. The town itself is located close to two active geothermal fields which makes for a very unique experience for both the eyes and the nose.

Intrigued? Check out our detailed guide, Top things to do in Rotorua.

Auckland

Location: Auckland Region
Type: Volcanic Field
Last eruption: Around 600 years ago

Looking at the city from ground level, you wouldn’t actually know that it sits on top of a volcanic field and is home to over 50 volcanic cones and craters. Today, many of these cones are popular visitor attractions with One Tree Hill and Mount Eden offering great panoramic views of the city.

The largest volcanic feature in the area is Rangitoto Island, located just off the coast of Auckland’s North Shore. Rangitoto erupted around 600 years ago and was the only Auckland eruption that’s ever been witnessed by humans.

A short ferry ride will take you to the island and there is a scenic walk to the summit through pōhutukawa forest and lava fields.

To find out more, check out our detailed guide, Top things to do in Auckland.

Taranaki

Location: Taranaki Region
Type: Stratovolcano
Last eruption: Around 1854

Located on the south west coast of the North Island, Mount Taranaki (Mount Egmont) is an excellent example of a cone-shaped stratovolcano. At 2,518 m (8,261 feet) it’s also the second highest mountain on the North Island.

Taranaki hasn’t erupted since 1854 but prior to that, the largest eruption occurred in 1655 with tephra from that eruption falling across much of the central North Island.

To find out more about the region, check out our detailed guide, Top things to do in Taranaki.

Northland

Location: Kaikohe-Bay of Islands, Puhipuhi and Whangarei, Northland Region
Type: Volcanic Fields
Last eruption: Around 43,000 years ago

There are three main volcanic fields in the Northland region, Kaikohe-Bay of Islands, Puhipuhi and Whangarei but there hasn’t been any activity in these fields for many thousands of years. While not particularly obvious unless you know what you’re looking for, the Northland landscape does feature the remnants of numerous volcanic cones and lava fields.

To find out more about the region, check out our detailed guide, Top things to do in Northland.

Okataina

Location: Rotorua Region
Type: Lava Dome
Last eruption: June 1886

Located to the east of Lake Rotorua, this region’s main attraction is Mount Tarawera which tragically, was the site of the most lethal eruption in New Zealand’s recorded history.

In June 1886, the mountain literally ripped itself apart, opening up a 17km long rift. When magma from this eruption came into contact with nearby Lake Rotomahana, huge explosions covered the area in up to a metre of mud and ash, burying three villages and killing 108 people.

Today it’s possible to visit the remains of Mount Tarawera and having visited ourselves, it’s an experience we highly recommend. You can read more about our visit here, Visiting Mount Tarawera.

Mayor Island (Tūhua)

Location: Bay of Plenty Region
Type: Caldera Volcano
Last eruption: Around 6300 years ago

Mayor Island is located approximately 40km (25 miles) off the coast north of Tauranga, the largest city in the Bay of Plenty Region. The exposed summit of this volcano is dominated by a large caldera that contains numerous vents and there have been at least 52 recorded eruptions in the last 130,000 years.

Today, Mayor Island is a wildlife refuge and access is only possible by private charter and with the approval of the island’s caretaker in residence.

Extinct volcanoes

We’ve already mentioned several extinct volcanoes like the cones in and around Auckland, and while there are too many extinct volcanoes throughout New Zealand for us to mention here, in this section we’ll list a handful of the ones you may encounter on your travels around New Zealand.

Mount Maunganui

Located in the North Island coastal city of Tauranga, Mount Maunganui is a large lava dome that dominates the end of the peninsula to the north-east of the city. There is a short walk to the 232m summit which takes around 40 minutes and you’ll be rewarded with great views of the city and the stunning coastline.

Poor Knights Islands

The Poor Knights Islands are the remains of volcanoes created during the earliest eruptions of the Coromandel Volcanic Zone, between 9.5 and 10 million years ago. Located about 21km (13 miles) off the east coast of the North Island, the Poor Knights is today a marine reserve and considered to be one of the best spots in New Zealand for scuba diving and snorkeling.

Mount Tauhara

Given that this is our local mountain here in Taupō, we couldn’t possibly ignore Mount Tauhara. Formed around 65,000 years ago, this lava dome volcano dominates the skyline to the east of Taupō. There is a walking track that will take you to the summit of Mount Tauhara and while it’s a bit of a climb, the views from the top are spectacular.

Akaroa and the Banks Peninsula

In contrast to the relatively flat plains of the east coast of the South Island, when viewed from above, the Banks Peninsula to the south east of Christchurch is distinctly volcanic. The eroded remains of ancient shield volcanoes, this peninsula would have formed as offshore islands which are now connected to the mainland.