What’s inside the only accessible volcanic magma chamber in the world?

There is one volcano unlike any other. Normally, after a volcano eruption, its craters and the chamber below, filled with magma during the eruption, are closed off by lava and become inaccessible. But in Iceland, there is a unique volcano in which the magma chamber remained empty.

After the last eruption of the Þríhnúkagígur volcano, 4000 years ago, the lava drained down from the magma chamber that has remained hollow since. It provides a unique opportunity to see with your own eyes what the insides of a volcano look like.

This Voiij by community member Dration is a first-hand adventure into the heart of the volcano. Experience the full Voiij on the app here and check out their profile to see more of Dration’s informative explorations.

Þríhnúkagígur is located in the south of Iceland in the Bláfjöll region, not so far from Reykjavik. It is a dormant volcano, which is a part of Icelandic volcanic system, that marks the Mid-Atlantic ridge, where the Eurasian and North American plates are slowly moving apart.

The path to the top of the volcano begins in the lava field, filled with once-disturbed lava. Numerous caverns and caves indicate the violence of the lava flow during the volcano’s active period, 4000 years ago.

The entrance to the volcano is through the cone, where lava once flowed. A cable car is mounted at the exit of the tunnel at the beginning of the season and is used to transport the equipment and people down. The car passes the opening and enters the shaft. It takes 6 minutes for the car to pass 120 meters down the volcano.

This is the heart of the volcano.

The sheer size of the magma chamber is hard to comprehend, so here is a Statue of Liberty for scale. And the chamber itself is a size of 3 basketball courts, while the volcanic passages continue to a depth of 200 meters.

And inside the chamber, a spectacular show of colors takes place. These photos are not edited, and I tried to keep the white balance natural, so these are the real colors of the mineral residue that lava left on the walls.

The yellow color comes from sulphur, reddish hue is an oxidized iron, orange hue is due to the copper present in the lava.

Apart from the breathtaking colors, there are structures on the wall that show the flow of magma. Yes, technically, it’s not lava; it’s magma since it never left the volcano. You can see how it was dripping down the vent. This one is at the very opening of the vent, so it cooled quickly after the eruption stopped, retaining this fluid-like structure.

The floor of the chamber is uneven, with big rocks lying on the ground. In the center, beneath the main vent, there is a raised area consisting of a pile of rocks and magma, and the chamber becomes deeper near the walls.

If you look up, you can see the light coming from the smaller vents. And if it rains outside, it also rains inside, with the water coming through the open vents and dripping through the cracks in the stone.

The lift is going down, you can see the cables hanging down the wall.

The “lift shaft”: A cage designed to carry 6-7 people and equipment passes easily through this seemingly narrow shaft. This is how colossal the whole structure actually is.