Cueva de los Verdes

Partway through the tour the guide asks the group to keep what comes next to themselves, and it is worth going in without looking it up.

Before that comes the tube itself. Lava from Monte Corona ran through here about 3,000 years ago, and when it drained away the cooled crust stayed behind as a roof. Coloured lights pick out the texture of the walls as the path winds through narrow passages and wider chambers. In about 20 places the roof has fallen in, and one of those openings, a jameo, is the way in.

Near the entrance and exit sits a concert hall in the rock, with seats for up to 500 people. The two kilometres on the tour are only part of a system that runs 6 km inland and on under the sea. For centuries people from all over Lanzarote hid down here from pirates.

• Book online and arrive about 15 minutes before your entry time. The wait at the entrance is in full sun.
• There are no shops, cafés or food on site, so bring water. Toilets are outside the cave.
• Some passages are tight with low ceilings: hard going if you are claustrophobic.
• Not suitable for wheelchairs, pushchairs or anyone with significant mobility problems.
• Groups are large and music plays in parts of the cave, so the guide can be hard to hear. Stay close to the front.

The cave lies in the Malpaís de La Corona lava field in the north of Lanzarote, about 800 m from Jameos del Agua. Most visitors come by car: the cave's own car park is about 80 m from the entrance, staff direct the cars, and toilets stand beside it.

By bus, the nearest stop is Jameos del Agua, about 730 m away in a straight line.

Once you are there, everything happens on foot underground, with your guide. The whole visit takes an hour to an hour and a half, over steps and through narrow passages, so wear proper shoes.

Best: a hot, windy or grey day, when the beach has little to offer.

Avoid: the middle of a hot day if you are arriving without water and a hat.

Underground the tube keeps one temperature whatever the weather is doing above it, while the queue at the entrance stands in the sun and there is nowhere on site to buy a drink.

Entry is by guided tour only. Groups go in together with a guide who speaks Spanish and English, and you stay with the group the whole way through. Dogs are not allowed. The cave lies inside the Malpaís de La Corona Natural Monument, a protected area of the Canary Islands.