There are few dive sites in Sinai more spectacular – or more dangerous – than Blue Hole. This circular, 125m drop off looks exactly like its name. The dark hole rests in the shallows of a bright blue reef shelf, and the life clinging to the hole’s rim is unusually dense. Corals, fans, eels and dozens of fish species flourish here, and the space-like depths of the hole provides a magnificent backdrop. It is best, however, not to let the Blue Hole’s dark beauty lure you too far down: more than a few people have gone in and never come back, due to nitrogen narcosis.