Víðgelmir Lava Cave: Touring Iceland’s Biggest Cave

Víðgelmir is the largest lava cave in Iceland by volume, and it sits about 45 minutes’ drive up the Hvítá valley from the Hvítá Inn. If you are doing the Borgarfjörður circuit by car, it is the closest big underground tour to the inn, tucked into the Hallmundarhraun lava field near Húsafell.

What the Tour Is Like

The cave runs roughly 1,585 metres into a lava tube left behind by the Hallmundarhraun eruption around 900 AD. The roof collapsed near the north end, which is why there are only a couple of natural openings, and the cave is gated, so you can only go in on a guided tour that starts from the base at Fljótstunga farm. Guides hand out a helmet and a headlamp, and a boardwalk with stairs runs deep into the tube, so you are not scrambling over raw lava in the dark. The standard tour takes about 1.5 hours and moves at a relaxed pace, with the guide stopping to explain the lava formations, the colours in the rock, and the mineral deposits along the way.

Winter Ice vs Summer Colour

The cave stays cool and dry year-round, which is what preserves its features. In winter, meltwater freezes near the entrance into ice columns and floor formations that can be metres tall, so the first stretch of the tour feels genuinely icy. In summer, that ice recedes and the draw shifts to the deeper cave, where the walls show off rust-reds, oranges and yellows from the minerals in the rock. Either season is worth it; they simply show you different things.

Pairing It with Húsafell

Fljótstunga is just past Húsafell on road 518, so the sensible plan is to make one loop of it. Drive up in the morning, do the cave, then stop at Húsafell for lunch or a soak, and take in Hraunfossar and Barnafoss waterfalls on the way back down the valley. That fills a full day out of the inn without doubling back.

• Getting there: About 45 minutes from the Hvítá Inn via roads 50 and 518, past Húsafell to Fljótstunga farm.
• Duration: The standard tour runs about 1.5 hours; allow extra for the drive and photos.
• What to bring: Warm layers and sturdy shoes with grip — the cave is cold and the boardwalk can be damp. Helmet and headlamp are provided.
• Timing: Tours run year-round; book ahead, as it is guided-only and small groups fill up. Check the current schedule and prices at thecave.is.

Where to Stay

The The Hvítá Inn sits right on the bank of the Hvítá river at Hvítárbakki, which puts you at the mouth of the valley the cave sits in — you drive straight up road 518 instead of coming all the way from Reykjavík, so you can catch an early tour and still be back for dinner. Rooms have private bathrooms, and the inn is about 75 minutes from Reykjavík on the way west. Book direct on Ourhotels.is for the best rate.

Photo: Olikristinn via Wikimedia Commons, CC BY-SA 3.0.