The Palace of the Dukes of Urbino is one of the most important monuments in Italy, it's been listed as a UNESCO World Heritage Site since 1998
The construction of the Ducal Palace was begun for Duke Federico III da Montefeltro around the mid-fifteenth century by the Florentine Maso di Bartolomeo. The solid rock hillside salient was impregnable to siege but was problematic for carving out the foundation of a palace. Thus, a prominent fortress-builder, Luciano Laurana, from Dalmatia, was hired to build the substructure; but Laurana departed Urbino before the living quarters of the palace were begun. After Laurana, the designer or designers of the Ducal Palace are not known with certainty.