Þríhnúkagígur Volcano

The magma that once filled Þríhnúkagígur drained away and left the chamber under the crater empty. An open lift carries visitors from the rim down to the floor, 213 metres below, through a space covering 3,270 square metres. The rock walls are strongly coloured, and photographs flatten them. At the bottom a roped-off path keeps you to one part of the floor, and the guide stays close by. No other volcano in the world lets you do this. In 2015 the Icelandic band Kaleo descended with fourteen support staff and recorded a live version of "Way Down We Go" on the chamber floor.

• Book ahead — the Inside the Volcano tour, run by 3H Travel, is the only way into the magma chamber.
• The lift is open — you ride down in a safety harness clipped to the car, and stay on a roped-off path at the bottom.
• Snow makes the walk hard work — the route to the crater is long in any conditions and heavier under snow.
• Soup at base camp — Icelandic soup is served there as part of the tour.
• Toilets on site, and cards are accepted, contactless included. The volcano is not set up for young children.

Everything from the meeting point is on foot. First a long walk out to base camp, then a climb up the cone to the lift. The lift covers the last 213 metres, straight down. The same walk brings you back afterwards, so keep something in reserve for the return leg.

Better: when the ground is clear of snow, when the walk out to the crater is at its easiest.

Avoid: snowy conditions, unless you are happy with a long walk that turns into a workout.

What changes through the year is the approach, not the chamber. The magma chamber is underground and looks the same in any weather. The walk to it and back is the part that will tire you out.