In 1473, a ruined fortified house at Poggio a Caiano called the Ambra, and land and a mill owned by Giovanni di Paolo Rucellai, were bought by Lorenzo de' Medici. Initially, only agricultural improvements were carried out; then in 1485, work began on the villa itself, to designs by Giuliano da Sangallo, who created a large fortified, quadrangular country house built around a central courtyard. A large central hall gave access to rooms with windows overlooking the surrounding countryside; at the time, this design was innovative.