The distinctive features of Castello Estense (or Castello di San Michele) are four fortified towers and a moat with a drawbridge. The whole brings to mind the original function of this palace: a defensive fortress.
And that was the original intention for Castello Estense in Ferrara. The palace was built just 16 months after a riot caused by Ferrara citizens protesting against high taxes. The d’Este family hated at the time, commissioned the construction of a fortress to protect them from an attempt on their lives.
As the centuries passed, however, Castello Estense was extended with the comfort of its inhabitants in mind. Therefore, apart from the apparent Gothic original inhospitality of the outer façade, some changes were made. Examples are decorative balconies and roof terraces. The rooms inside the castle were also expanded. From the 16th century, Castello di San Michele came under papal authority.