Pienza, in the province of Siena, is one of the rare projects of "ideal city" of Renaissance put into practice. Its urban planning project, curated by Bernardo Rossellino for Pope Pius II, is one of the most significant achievements of Italian fifteenth century and is worth mentioning UNESCO World Heritage Site in Historic Center of Pienza. The initial project had to concern only the central square, where Cathedral, papal noble palace, the seat of the municipality and the bishop of Pienza stood out. The intervention was then extended to the rest of the village: Rossellino placed the square in a tangent position to the main street, at the point where the axis bends and the ground extends towards Val d'Orcia, placing in its space Duomo, on the longer side; Palazzo Piccolomini, on the right; Palazzo Vescovile, on the left and at the end, over the road, Palazzo Pretorio. The pavement is in terracotta, divided into squares by travertine planks that create a perspective graticule.