Iceland Lava Cave & Lava Tunnel Tours

Everything you notice underground follows from the draining. The horizontal lines running along the walls at shoulder height are lava marks, the level the flow held before it dropped, exactly like a tide line. The ceiling in places is hung with short stubby stalactites, which are not mineral deposits but rock that melted and re-froze from the roof while the tube was still hot. The floor is often ropy and folded because the last of the lava congealed as it moved.

The colours come from oxidation and from the minerals in the rock. Raufarhólshellir runs red, purple and yellow in the sections where iron has weathered, and green where a thin skin of moss has crept in near the collapsed openings. Those collapses matter: a lava tube is lit only where the roof has fallen in, and every commercial cave in Iceland uses one of those holes as its entrance. In winter the light coming down through them lands on ice sculptures a few metres inside, formed by meltwater freezing as it drips, which is the one genuinely seasonal thing about these tours.

Raufarhólshellir is 1,360 metres long, up to about 10 metres high and 30 metres wide in the larger chambers, and it drained roughly 5,200 years ago out of the Leitahraun flow that came from east of the Bláfjöll mountains. It is a thirty-minute drive from Reykjavík on Route 39, it is open every day of the year, and there is a footbridge and a lighting scheme through the first section. Five listings on this page take you into it, and the hour you spend inside is the same hour in all five.

Two things fall out of that table and neither is flattering to the top of it. The 73 EUR spread buys nothing but a seat in a vehicle, and the cheapest option is also the highest rated, on more reviews than the other four combined. And the most expensive option is the lowest rated on the entire page at 4.2, which for a product whose only added value is transport is a fairly direct verdict.

If you have a rental car, drive. The cave has a car park, the tours run at fixed times through the day, and 52.70 EUR is the honest price of this experience. If you do not have a car, the 103.00 EUR option is the one to take: it is the cheapest of the transported versions and the only one with enough reviews to trust.

This is the single most common misunderstanding on this page, and it is nobody's fault: the photographs used to sell the standard tour are usually taken on the adventure one.

The standard tour is about an hour, follows a constructed walkway with permanent lighting through the first third of the cave, and is suitable for anyone who can manage stairs and uneven ground. You are handed a helmet and a head torch, you walk, you stop, the guide talks, you come out. It is a good hour and it is not caving.

The adventure tour runs three to four hours, leaves the walkway behind and continues to the far end of the tube where the Lava Falls are, over collapsed roof blocks, under low sections, in the dark except for what you are carrying. It costs more, runs less often, and is the version in which the cave stops being a museum. If the phrase in a listing is explore the full length or reach the Lava Falls, that is the one you are buying.

Booking the standard tour and expecting the adventure one is the commonest disappointment here. Booking the adventure tour in trainers is the commonest way to be turned around at the entrance.

Víðgelmir is the largest lava cave in Iceland: 1,585 metres long with passages reaching about 15.8 metres high and 16.5 metres wide, which is a different order of space from Raufarhólshellir. It sits in the Hallmundarhraun lava field in Borgarfjörður, in the west, in a flow that erupted around 900 AD. That date is not incidental: Iceland was being settled at the time, and archaeologists have found evidence of Viking Age occupation inside the cave. An iron gate was fitted in 1991 to stop the remaining mineral formations being broken off, which tells you what the previous decades had been like.

The problem is distance. Víðgelmir is roughly two hours from Reykjavík in the wrong direction for everything else, so it only appears here inside longer trips. The 201.92 EUR Silver Circle day pairs it with the Hraunfossar and Barnafoss waterfalls, the Deildartunguhver hot spring, which operators describe as the most powerful in Europe, and a horse farm at Sturlureykir. The 475.26 EUR listing is two days and adds the Snæfellsnes peninsula. Both are rated 4.9, and both are really touring days that happen to include the best lava cave in the country.

The third cave that gets named in this market is Leiðarendi, near Bláfjöll, which is smaller, unlit and sold as a caving trip rather than a walk. It does not currently appear in the listings here. If you find it elsewhere, treat it as the adventure tier by default.

Every listing on this page includes a helmet and a head torch, and none of them includes clothing. The temperature inside a lava tube stays close to the annual average outside, which in Iceland means cold and, more importantly, unchanging: the cave is the same in July as in February, so a summer visitor in a T-shirt is the one who suffers. A fleece and a waterproof shell are enough for the standard tour.

Footwear is the thing that actually matters. The floor is broken basalt with a texture somewhere between gravel and broken glass, it is wet in most seasons, and ankles turn on it. Hiking boots for the standard tour, boots with a proper sole for the adventure one. Gloves are worth having on the adventure tour because you will use your hands, and the rock is abrasive enough to take skin off a palm.

Two last practical notes. There is no phone signal underground, so anything you need has to be downloaded before you go in. And the standard cave lighting is deliberately dim, so a phone camera will struggle; the good photographs from these tours are almost all taken by guides with proper lamps, which several operators do and include.

These tours run twelve months a year and the cave does not care what the weather is doing. Raufarhólshellir is open every day, the drive is on a main road that stays ploughed, and the interior temperature barely moves between January and July. This is the standard wet-weather answer in southern Iceland, and one listing leans into it directly by pairing an evening cave visit with a northern lights hunt afterwards at 181.00 EUR, which only works between about September and March.

The one genuine seasonal difference is the ice. Meltwater dripping through the collapsed entrances freezes into columns and sheets a few metres inside during winter, and those are gone by late spring. If ice formations are what you saw in the photographs, go between December and March.