Ice caves in Iceland: when, where, how to book, and which one

Three different things are sold as ice caves; they are not interchangeable.

The crystal caves form in the summer melt under the glacier and are safe to enter only once the meltwater stops and the ice freezes solid, which is usually mid-November, and they become unsafe again when the melt starts, usually in March. In a warm autumn the season starts in December; in a cold spring it runs into early April. Operators announce the opening each year and the caves change every year.

The Katla cave and the Langjökull tunnel are open all year because one is ice under volcanic ash that insulates it and the other is man-made inside the ice cap; both are a different, darker experience from the blue caves.

All the crystal-cave tours leave from the Jökulsárlón car park, 380 km from Reykjavík. A day trip from the capital is 10 hours of driving and is sold, but the sensible version sleeps within an hour of the lagoon the night before and the night after, which also puts you at the lagoon and Diamond Beach at dawn. Katla tours leave from Vík, 190 km from Reykjavík, which works as a day trip with an early start or as the middle of a South Coast two-day. Langjökull leaves from Húsafell, 130 km from Reykjavík, a day trip.

The crystal caves have a few operators with a few departures a day, and the morning ones go first.

• Book four to eight weeks ahead for a date you need, longer for Christmas week and February half-term.
• Book the tour before the hotel near the lagoon, then the hotel to match; both are scarce, the tour more so.
• Pick a morning departure with a spare afternoon: tours are cancelled in storms and the operators move you to the next slot, which only helps if you are still there.
• Small-group tours cost more and spend longer in the cave with fewer people in the photos.
• Winter weather closes the Ring Road a few days a year; give the cave day a spare day on either side.

The operator supplies crampons and a helmet; you supply everything else.

• Waterproof boots with ankle support (no trainers), waterproof trousers and shell, warm layers, gloves and a hat; the cave is at 0°C and drips.
• The ride is in a modified 4x4 over rough glacier moraine, bumpy and slow; the walk is 20 to 40 minutes on uneven ice with crampons.
• Children from about 8 are accepted by most operators; the Langjökull tunnel takes all ages.
• The blue is best in flat, overcast light and in the morning; sunshine on the glacier above makes the cave glow less, not more.
• Phones work for photos; a wide lens and a small tripod work better, and the guides know the angles.

If you are in Iceland between mid-November and March and can sleep near the lagoon, the crystal caves, without hesitation. If you are there in another month, or your trip stays on the western South Coast, Katla is a real cave and a good day, darker and more volcanic than blue. If you are based in Reykjavík with one day and want to stand inside a glacier, Langjökull. Doing two is for enthusiasts; the glacier hike at Skaftafell is the better second ice experience.