The Fortezza da Basso was built in the 16th Century on the orders of Alessandro de Medici who appointed himself duke of Florence. It was designed by Antonio da Sangallo and was later known as a ‘prison and slaughterhouse’ due to Alessandro’s brutality. The fort was later used as a gaol and barracks, and eventually fell into disrepair. In 1978, a building was erected in the fort complex which is used for shows and trade fairs. There are gardens here open to the public.