Vatnajokull ice cave tour: inside the largest ice cap in Europe, and when it is open

The cap sends tongues down to low ground, and in the warm months meltwater runs through and under those tongues. When the cold arrives the water stops and some of what it carved is left standing: a hollow, a tunnel, sometimes a room with a ceiling of dense blue ice. That is the whole mechanism, and everything about how a Vatnajokull ice cave tour is sold follows from it. The caves are natural, they are different every winter, and they are found rather than built.

Which is why the window is fixed. Roughly November to March. Operators here do not run natural caves outside it, and no fare gets you into one in July. What does run all year is the walking on the outlets, and the Katla cave two hours west at Mýrdalsjökull — a different glacier entirely, with ash in its ice.

Two meeting points, one body of ice. Four listings meet inside the national park at Skaftafell and pair a walk on a tongue with a cave underneath it: $158 is the cheapest of them. Ten meet at Jökulsárlón, an hour further east, where the Breiðamerkurjökull outlet reaches the lagoon, and those lean towards a super jeep on a track and a shorter walk at the end. Anyone comparing an Iceland Vatnajökull tour from one town against the same thing from the other is really comparing an hour of driving, not two glaciers.

The names are working titles. Crystal cave, blue cave, the original cave: these are what operators call the ground they found this season, not fixed addresses. $163 and $172 use the first, $169 the second, and its listing leans on four generations of glacier work rather than on the name. Book by meeting point, length and company, and the names stop mattering.

What nobody promises. Not the colour, not a dry floor, not an empty room. Blue is what dense ice does to light, and the same cave reads differently from one week to the next depending on the snow above it and the weather outside. Every listing here promises a naturally formed cave; the photographs were taken on some other day.

A super jeep is a vehicle. It exists to get a group off the tarmac and onto a track that reaches the edge of the ice. The cave is still entered on foot, and the walk in can be a few minutes or the better part of an hour.

Our top pick: $195. Three hours, a jeep from the lagoon to a natural cave inside the cap, 4.6 from 962 reviews. It gives the cave the whole middle of the trip instead of treating it as the turn-around point of a walk, and it is the listing we would book first.

Cheapest under this ice: $158. Four hours meeting at Skaftafell, a guided walk on the cap and a naturally formed blue cave. The lowest fare of the twenty listings here, rated 4.6 from 21 reviews — young rather than proven.

Most reviewed on this ice: $164. 2,171 reviews at 4.2, three hours, ice caves under the glacier with the rugged south on the drive. The rating is lower than most here and the volume is higher, which is a trade-off worth seeing plainly.

Quietest: $310. Six hours, a 4x4 onto the largest glacier in the country, a hike to a remote cave and its ice canyons, the only 5.0 here from 264 reviews, and a listing that says outright it is built to avoid the crowds.

Smallest company feel: $173. Two and a half hours, 4.7 from 65 reviews, run by a small family firm, with a super jeep and a short scenic walk to the cave. The gentlest version of this day that still goes inside.

If you are coming from the capital: $698 is two days that take in a blue cave, waterfalls, black sand beaches and a walk on the glacier at Skaftafell. It is the highest fare on the site and the only listing that does not ask you to already be in the south-east.