The Sant’Anna, also known as the Drago, and to Polybius as the Hypsas (Ὕψας), is a small stream in the Province of Agrigento, southern Sicily. It flows through a deep valley until it reaches the ancient Greek city of Acragas (Agrigento), the lower part of which developed on a rocky scarp standing between this river and the San Biagio (then, like the city, called Acragas) to the east. The two rivers merge a little to the south to form the Fiume di Girgenti which enters the sea after a course of about a mile.