Rich in works of art and medieval architectures, Ferrara in the Renaissance period becomes a real gem through the work of some of the greatest Italian masters such as Piero della Francesca, Jacopo Bellini and Andrea Mantegna that were at the service of the Estense Court that have profoundly marked the history of the city. In 1995 it was appointed by UNESCO World Heritage Site together with the Po Delta, which is inserted in 1999. The urban planning expressed in Ferrara was deliberated by the Este family: the Addizione Erculea (Herculean Addition), marks the first example of urban planning which gives the city a particular development on a linear axis along the banks of the Po with longitudinal streets and intersections. To make the splendor of Ferrara there are numerous monuments, unique among all the San Michele Castle or Castello Estense. The castle was built in 1385 by the court architect Bartolomeo da Novara and ended in 1570 becoming an aristocratic residence with large living rooms and marble balconies. Joint to the Castle by a covered inner path, the Town Hall dates back to around 1200 and was the ducal residence of the Este. Now is the seats of the town hall, the Palace looks out on the Cathedral Square. Of great value, finally, the Po Delta Park, a natural oasis surrounded by the “Este Delights”, set of 30 villas and hunting retreats built in this area, which testify to the influence of the Este family.