These are formed around grains of sand and they become coated with calcium carbonate which can grow in time to be 3 cm in diameter.

A moving body of water is required to keep these pearls turning whilst they form.

[2] Pete’s Paradise is a unique structure with crystal-clear rim stone pools and a maze-like network of crawls and chambers.

During excavation in 1966 numerous prehistoric artefacts were found such as shards of Neolithic pottery, bones and stone tools.

This cave was only discovered in 1966 but surveys have shown that many of the stalactites have been broken off and the pools have been stirred.