A grotto is a natural or artificial cave used by humans in both modern times and antiquity, and historically or prehistorically. Naturally occurring grottoes are often small caves near water that are usually flooded or liable to flood at high tide. Sometimes, artificial grottoes are used as garden features. The Grotta Azzurra at Capri and the grotto at the Tiberius' Villa Jovis in the Bay of Naples are examples of popular natural seashore grottoes.