Originally built to defend the city of Siena, the Santa Barbara Fort is constructed in brick. It was commissioned by Cosimo I de Medici and built in 1560 to a design by Baldassarre Lanci. The fortress was restructured in 1937, when the gardens on the ramparts were arranged in order that visitors could enjoy the magnificent views of the city and the hills from the heights of the bastions. Today the Santa Barbara fort is still open to the public for walks.