The toponym derives from the moat surrounding the Castle for defensive purposes. The terrain morphology consisted of a ditch at the base of the small hill on which the Castle stood, extending from west to east, now known as Via Pizzofalcone.
The name Piazza Fosso remained unchanged until 1932 when it was changed to Piazza Principe di Piemonte in honor of Umberto di Savoia (future Umberto II, the “king of May”) passing through Badolato in May 1932 to visit the family of the Marquis of France. Badolato was not the destination for the Princess, but they passed through because the S.S. 106, under construction, was still accessible to Badolato Marina.
After the referendum of June 2, 1946, with the exit of the House of Savoy from the scene, the square once again returned to be called Fosso.
In one corner, there is one of the two existing marble monuments in Badolato, dedicated to Antonio Tropeano (1865 – 1949), a physician who was close to the people of Badolato. He served as a Sanitary Officer for a certain period and was well-known and respected at the provincial level.