Walk inside a lava tube

Just 30 minutes from Reykjavík, The Lava Tunnel offers a rare chance to step into one of Iceland’s longest and best‑known lava tubes, Raufarhólshellir. Open all year, it is easily reached from the city yet feels like a journey deep into the volcanic heart of the country.

An impressive underground world

Raufarhólshellir stretches for about 1,360 metres (4,500 ft), with the main passage running some 900 metres (3,000 ft). In places the tunnel is up to 30 metres wide and around 10 metres high, making it one of the most expansive lava tunnels in Iceland. Near the entrance, parts of the roof have collapsed, creating striking shafts of natural light that illuminate the cave. Deeper inside, the tunnel branches into three smaller passages where dramatic lava falls and intricate formations can be seen.

Formed by a powerful eruption

The Lava Tunnel was created during the Leitahraun eruption, over 5,000 years ago. As low‑viscosity lava flowed from the volcano, a solid crust formed on the surface and gradually thickened into a roof, leaving a molten river running beneath. When the eruption ended and the lava drained away, it left behind the hollow tube we explore today. In the past, the cave was lined with delicate stalactites, but increasing visitor numbers in the mid‑20th century caused most of them to disappear, making current conservation efforts all the more important.

A guided journey beneath the surface

A visit to The Lava Tunnel is a guided experience that reveals the raw forces shaping Iceland. Walking along the illuminated path, you can see how lava once surged through the tube, carving out walls, ceilings and lava falls. It is a unique opportunity to witness the aftermath of a volcanic eruption from the inside and to discover the hidden world that lies just below the surface of the lava field.

Experience The Lava Tunnel

Whether you choose a standard walk or a longer adventure tour, The Lava Tunnel combines accessibility with genuine geological wonder. It is an ideal addition to a day trip from Reykjavík and a memorable way to experience Iceland’s volcanic landscape from within.