Lake Sassano is an unusual natural feature in Conversano's territory: a karstic doline — a depression formed by the dissolution of the underlying limestone — that fills with water seasonally. It sits just west of the town and is one of the few natural lake habitats in a region dominated by limestone that drains water quickly underground rather than collecting it on the surface.
The site is not a formal tourist attraction but provides a pleasant half-hour walk from the town through olive groves, and in winter and spring the flooded doline is an interesting geological curiosity. The surrounding countryside gives a good sense of the Murge plateau landscape — flat-topped karst plateau, ancient stone walls, and groves of olive trees whose gnarled trunks indicate centuries of cultivation.