St Michael's Cave, Gibraltar

A huge limestone cave high on the Rock of Gibraltar, with a great hall of stalactites and stalagmites lit by changing coloured lights. The main chamber is used as an auditorium for concerts. Legend once said the cave was bottomless and led under the sea to Africa, which explained how the monkeys reached Gibraltar.

Entry is included in the Upper Rock Nature Reserve ticket. Guided adventure tours visit the deeper Lower St Michael's Cave, with an underground lake.