The Cassero Senese is a 14th-century fortification located in Grosseto, Tuscany, Italy.
Built by the Republic of Siena, it survived the demolition of the Sienese fortifications ordered by Cosimo I de' Medici, Grand Duke of Tuscany in 1565 and was incorporated in the Bastione Fortezza of the Grosseto city walls.
Wikipedia https://en.wikipedia.org/wiki/Cassero_Senese
Address 6 Via Aurelio Saffi, Grosseto 58100, Italy
Coordinates 42°45'42.331" N 11°6'59.59" E