The Island of Capri is the pearl of the bay of Naples and surely the most famous Island in Italy. It is mountainous, with a precipitous limestone coast pockmarked by caves and fissures and eroded into fantastic natural sculptures. The island was occupied in prehistoric times and later by the Greeks and Romans. Today Capri is under siege from tourists although thankfully the harbour is left pretty much alone by sight-seeing tourists. It is worth a trip to see the famous Blue Grotto, a marine cavern on the north-west coast that was once a "nymphaeum" of Tiberius. Under 2m of water, there are niches, platforms and apses carved out of the rock, indicating that the land had subsided considerably since Roman times.