Is the smallest city of Apulia with its own city council. Located in the Salento peninsula, Castro faces on to the Adriatic Coast. Founded by the Messapi (an ancient Italic population), the settlement was conquered by the Romans in 123 b.C. and named Castrum Minervae, in honour of a temple, built in the area, entitled to this Goddess and evidenced by traces found during the refurbishment of the castle area. Castro was one of the first cities of the Salento to be proclaimed "County" and became a bishop's seat under Pope Leone II in 682.

At Castro Superiore, between the typical medieval streets and the small houses, arises the Castle, built in the XIII century in a rectangular shaped plan with 4 towers; fortified walls; a Cathedral, built in 1171, on the ruins of an antique temple. In the district of Castro Marina, green olive tree orchards are the frame of a pretty port setting, so near to Greece, to offer the opportunity to smaller boats to reach their trading destinations there.

Castro is also famous for its caverns (grottos): the Grotta Zinzulusa (known with this name due to the chalky rocks that hang from its ceiling), with a large sea entrance, where traces of animals (elephant and "speleo" bear), and of swords and ceramic exhibits have been found, which evidence that the cavern was inhabited by people; the Grotta Romanelli, also situated along the coastline and is one of the most important Italian Prehistoric seams with red painted graffiti.