Iceland’s largest lava cave is 10 minutes from Hraunfossar. Most visitors drive straight past it. This tour doesn’t.
The Silver Circle follows the base route — a brief stop in Borgarnes for fjord views, then Deildartunguhver, Reykholt, Hraunfossar — before adding a guided walk through Vidgelmir, a lava tube stretching over 1,500 metres. The cave was formed in the same Hallmundarhraun eruption that created the lava field at Hraunfossar. Your guide makes the connection explicit: you see what the lava did above ground, then you descend into the tube it left behind.
The cave is professionally lit and guided by a specialist cave guide who handles the underground section. Stalactites, ice formations (in winter), lava pillars, and chambers where the ceiling reaches 10 metres. The walk takes about an hour. The temperature inside is cold year-round (approximately 4°C) — bring a warm layer even in summer.
Helmets and headlamps are provided on-site.
The Silver Circle gives you Iceland above ground. Vidgelmir gives you Iceland below it.
The Silver Circle route + a guided walk through Vidgelmir — Iceland’s largest lava cave. See the lava above at Hraunfossar, then walk through the tunnel it left below
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