Atlántida

The whole dive is built around one formation — a triangular reef of hexagonal basalt columns, some still standing and some collapsed across each other — and the boat ride to it from Los Gigantes takes about three minutes. Drop onto the shallow end of the structure around 16 metres and work down the columns rather than wandering off the rock, because the deep side bottoms out near 30 metres and bottom time goes quickly once you are there.

Yellow gorgonians grow on the exposed faces and a small cave in the formation holds African grunts, with local bream that tend to follow divers along the rock. Octopus sit in the cracks and greater slipper lobster tuck under the ledges; both take a slow pass and a torch to pick out of stone the same colour as they are, and groupers hold off the structure in open water.

With an average working depth around 28 metres the columns get one pass rather than two, so start deep at the outer end and let the route climb back along the reef towards the shallow corner. Finish the dive on the top of the formation at about 16 metres, where the safety stop can be spent over the rock instead of in blue water.