The city is known worldwide for its underground karstic cavities, located about a mile from the town and periodically visited by thousands of tourists.
The Caves of Castellana are developed for over three kilometers through caverns, stalactites, stalagmites, echoes and concretions, up to the spectacular White Cave that enchants with all its splendor.
Among the most precious assets of the city also the Church of the Madonna della Grotta, the only example of an underground church with a stone altar dating back to the mid-1700.