Castellana Grotte, located on the limestone plateau of Terra dei Trulli and Grotte, is known above all for karstic complex of Castellana Caves. Turist visit winds along a fascinating scenery for more than a 1 km: natural entrance consists of a huge open pit, about sixty meters deep, called Grave. From the Grave you reach extraordinary Grotta Bianca, called the most beautiful cave in the world, bright and shining. Ancient part of Castellana, urban-medieval type, is characterized by numerous lanes, churches, palaces, arches and white houses. Largo Portagrande coincides with the most depressed point of a large rain basin, where "gravinelle" open up, natural incisions of calcareous rock; on the opposite side, Casalicchio district annexed to former convent of Paolotti friars. Torre Nuova, commonly called Castello, is a cylindrical bastion of the fifteenth century, the only survivor of old defensive walls together with the walls. Festa d'Aprile is the most solemn event of Castellana, including lights, processions, concerts of various bands and fireworks.