The giant caldera of Ambrym Volcano has several craters. Up to recent time here were located two of the few lava lakes of the world – one in Benbow Crater and another in the nearby Mbwelesu Crater.

Giant volcano

The island of Ambrym is a volcano – the whole island has been shaped by the basaltic Ambrym volcano. Sometimes around 190 AD (or somewhat later… or before this… exact date is not known) a giant volcanic eruption created the present-day Ambrym caldera which is some 12 by 8 km large.

Later in this caldera rose several craters – two larger ones (Benbow and Marum) and three smaller ones.

Plumes of ash from Benbow and Mbwelesu craters, December 2013
Plumes of ash from Benbow and Mbwelesu craters, December 2013. / Stuart Rankin, Flickr / CC BY-NC 2.0

Ambrym is one of the world’s most active volcanoes up to this day. It’s eruptions often are disastrous and local people from time to time (e.g. in December 1913) are forced to flee from the island.

Around the crater grows lush tropical forest with gorgeous orchids. Orchids grow in caldera as well. Closer to the craters, though, the land is empty due to frequent eruptions and acid emissions.

One should visit the volcano at certain times of the year with experienced local guides. There are cultural restrictions – many places are subject to seasonal taboo.

Acid rain

Acid rain from the craters of Ambrym is fairly common. Thus, in March 1979 from Benbow Crater rose a very destructive cloud of acid rain with sulfuric acid. Within 24 hours much of the vegetation in the south-west part of the island was lifeless, water supplies were contaminated. Some people got acid burns.

In November 2002 acid rain eliminated mango fields on the west coast. Frequent acid rains have caused a lack of suitable groundwater and locals are in a dire need of fresh water.

Lava lake in Benbow Crater

Over the last century lava lakes in the craters of Ambrym volcano have been observed several times. For several decades from the 1990ies until December 2018, there existed two lava lakes – one in Benbow Crater and one in a smaller side crater of Marum – Mbwelesu Crater.

In August 2018 there were even three lava lakes – a third one appeared in Niri Mbwelesu crater around January 2018.

The lava lake in Benbow crater could not be seen from the rim of crater and visitors had to descend in the crater and some dared to approach up to 100 m distance from the lake. But this trip hard was rewarding – the lava lake offered a view which is very, very rare on Earth.

The lava lake was rather small, some 40 by 30 m large. But it was in a constant movement with lava fountains and waves. Visitors stood at the crater and it was hard to leave…

After a powerful eruption and several earthquakes, all lava lakes of Ambrym volcano disappeared on December 16, 2018. We do not know if they will return…

Benbow Crater is included in the following article:

Lava lakes of the world
Lava lakes of the world in 2019
Lava lakes of the world in 2019 / Wondermondo / public domain
In October 2019 we have seven existing lava lakes on Earth. Three more existed for a longer time in the recent past. Besides this, since the year 2000 short-lived lava lakes and lava ponds existed in 11 more places. Wondermondo has listed them all in this article.


  1. Ambrym volcano. Accessed on June 10, 2019
  2. Smithsonian Institution, National Museum of Natural History. Global Volcanism Program. Ambrym. Accessed on June 10, 2019
Benbow Crater on the map
Travelers' Map is loading...
If you see this after your page is loaded completely, leafletJS files are missing.
Location, GPS coordinates: 16.2603 S 168.1042 E
Categories: Volcanoes, Lakes and streams, Places with meteorological phenomena
Values: Geology, Visual
Rating: 4.5 out of 10 stars
Where is located? Oceania, Melanesia, Vanuatu, central part of Ambrym Island, in Benbow Crater
Height: around 1,120 m

Video of Benbow Crater

Christopher Horsley, January 2019

Landmarks of Vanuatu

Lake Letas with Mount Gharat, Vanuatu
Lake Letas with Mount Gharat / , Wikipedia / CC BY-SA 2.5
Vanuatu is beautiful and impressive country. People of Vanuatu should be praised for the preservation of the natural landscape and their traditions thus showing that there is a noble alternative to Western civilization.


Mount Cleveland, Aleut Islands
Mount Cleveland / NOAA Photo Library, / CC BY 2.0

This category includes the most unusual and interesting volcanoes of the world.

Over the last 10,000 years in some 1,500 places around the Earth through the crust of the planet was emitted lava, ash, and gases from the mantle of Earth. Each of these places is an active volcano. Every year some 50 – 70 volcanoes are erupting, at any moment there are some 20 – 30 eruptions on-going.

Recommended books

Vanuatu: Far Flung Places Travel Guide

The only current detailed guide to the islands of Vanuatu, with invaluable information not just on the main islands, but also the more rarely visited outer islands. Including maps and detailed listings.

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