From the Torre dello Zancale in Marina di Camerota to Scario, there are almost 14,000 kilometres of coastline alternating between high limestone cliffs, inlets, small beaches, coves, underwater springs and submerged caves. Among the most beautiful beaches are Cala Bianca, Baia degli Infreschi, Marcellino, Sciabica and the Twin beaches. Along the cliffs grow coralligenous constructions, a kind of Mediterranean reef populated by a huge variety of colourful organisms such as sponges, madrepores, gorgonians and serpulas. The seabed is also home to expanses of Posidonia oceanica, among whose leaves lives the 'nacchera', a protected species of endangered bivalve mollusc, a sign of the posidonia's good conservation status. This stretch of coastline and more than 2000 hectares of sea are under the protection of the Protected Marine Area Costa degli Infreschi e della Masseta.