The historic man-made Pistoia Sotranya Caves are located below a historic hospital in the city dating back to the 13th century AD, one of Pistoia's most famous landmarks, and a place with a rich and long history. These caves were used as a room for teaching the anatomy of the human body, and in these caves also flowed the course of a river that the hospital was built directly above, and at the time it served as a sewage network for the hospital.