Raufarhólshellir Lava Tunnel

Just 30 minutes from Reykjavík lies one of Iceland's most expansive lava tunnels — a tube carved by flowing lava roughly 5,200 years ago, stretching 1,360 metres beneath the Bláfjöll mountains. Walk beneath shafts of daylight pouring through collapsed sections of ceiling, past rock walls streaked in red, purple and gold from mineral deposits and floodlighting.

Duration

1 – 4 hours

Location

30 min from Reykjavík

Tunnel Length

1,360 m (900 m main passage)

Formed

~5,200 years ago

Difficulty

Easy to moderate

Minimum Age

3 years (standard tour)

The Experience

A Guided Walk Underground

A professional cave guide leads the way along a lit footbridge and walkway, explaining how the tunnel formed during the Leitahraun eruption and pointing out its distinctive lava formations. Helmets and a torch are provided — no caving experience is needed.

A small guided group walks along a lit boardwalk deep inside the lava tunnel

Columns of Light

Near the entrance, three sections of collapsed ceiling let daylight spill straight down into the tunnel, lighting the rock in a way no photograph quite captures. In winter, meltwater dripping through these openings freezes into striking ice sculptures.

A visitor stands on rocks looking up at a shaft of daylight through a collapsed section of the tunnel roof

What You'll See

The main passage reaches up to 30 metres wide and 10 metres high before branching into three smaller tunnels at its far end, with lava falls and flow formations frozen in the rock. Standard tours cover the easy, lit section of the tunnel; the longer Lava Falls route heads off the main path into the tunnel's undeveloped depths for those wanting a real caving adventure.

Good to Know

Wear warm layers and sturdy, closed-toe shoes — the tunnel floor is uneven rock and can be slippery near the ice formations. Helmets are provided on every tour; the longer adventure route also requires a reasonable level of fitness and balance. Available year-round.