About 30 kilometres from Reykjavík, a dormant volcano called Þríhnúkagígur lets visitors do something almost nowhere else on Earth allows: step inside the actual magma chamber of a volcano. The tour is known as Inside the Volcano, and it ends with a bowl of Icelandic lamb soup back at the surface — though the descent is the real reason people come.
What makes Þríhnúkagígur special is its plumbing. In most volcanoes, the magma chamber solidifies after eruptions. Here, the molten rock drained away after the last eruption roughly 4,500 years ago, leaving a hollow cavity of around 3,100 square metres. The rock walls are stained in shades of red, orange, yellow, purple and blue — a colour record of the volcano's geological history. The chamber has been open to visitors since 2012.
The outing starts with a guided hike of about three kilometres across uneven lava fields, 45 to 50 minutes each way. At base camp you get kitted out with safety gear, then ride an open cable lift roughly 120 metres down into the chamber — the descent takes six to seven minutes. Once inside, you get around 30 minutes with a guide to explore the space before making the trip back up.
The soup, to be clear, is not served underground. It's waiting back at base camp, where traditional Icelandic lamb soup is ladled out (vegetarian and vegan versions available) along with coffee, tea and hot chocolate. After a cold hike and a descent into the earth, a hot bowl feels well earned. Simple, yes — but few meals come with a backstory like this.
Practically speaking, the tour runs from May to October, weather permitting. Allow four hours if you meet on site, or five to six with transfers from Reykjavík. You'll need moderate fitness, sturdy hiking boots, warm layers and waterproofs, and the minimum age is eight. Check the operator's site for current prices and departure times.
For travellers who've already ticked off Iceland's waterfalls and glaciers, this is a genuinely different angle on the country — not looking at a volcano from the rim, but standing inside one. It's a half-day adventure that pairs geology with a warming meal, and it works as a day trip straight from the capital.
