The Ubaldini family controlled as many as 32 castles and fortresses on the territory in the town of  Firenzuola.
Firenzuola,  like Scarperia, was a “terra nuova” desired by Florence in 1306 and founded in April 1332 to gain control over the road to Bologna. In 1341 the Ubaldini “burnt it to the ground and abandoned it” (Villani, Cronica). What remains is the southern gate, Porta Fiorentina, and the northern gate, Porta Bolognese. In 1373 the construction of the fortress was begun: it would be the home of the Podestà. Today the structure houses an underground museum dedicated to the art sandstone.
Cornacchiaia, “Castrum Rivi Cornuclari”, property of  Ugolino Ubaldini, in 1332 was expunged by the Florentines and demolished as was the nearby Castrum Castri.
In Castro San Martino we can still admire the medieval gate that gave access to this small village and traces of the ancient walls.