Ferrara, which grew up around a ford over the River Po, became an intellectual and artistic centre that attracted the greatest minds of the Italian Renaissance in the 15th and 16th centuries. Here, Piero della Francesca, Jacopo Bellini and Andrea Mantegna decorated the palaces of the House of Este. The humanist concept of the 'ideal city' came to life here in the neighbourhoods built from 1492 onwards by Biagio Rossetti according to the new principles of perspective. The completion of this project marked the birth of modern town planning and influenced its subsequent development.

Źródło: World Heritage Convention
http://whc.unesco.org/en/list/733