How Pienza was built and evolved over time

Pienza is the only town in this group where the question "how was it built" has a short answer: deliberately, quickly, and once.

The commission

From about 1459, Pius II had the village of Corsignano rebuilt as a designed town. The architect was Bernardo Rossellino, possibly working with Leon Battista Alberti. The cathedral was consecrated on 29 August 1462 — three years from commission to consecration, which tells you both how small the project was and how much money was behind it.

The square

Everything of consequence is arranged around Piazza Pio II, and the arrangement is the achievement. The square is a trapezoid rather than a rectangle, which widens the view toward the cathedral front. Four buildings define it: the Duomo, the Palazzo Piccolomini on the west, the Palazzo Vescovile raised by Cardinal Rodrigo Borgia, and the Palazzo Comunale facing the church. Each is designed to be read against the others.

This is what "humanist urban planning" means concretely: not grandeur, but a small space composed so that the relationships between its parts are legible from a single viewpoint. Pienza is the earliest surviving example, which is why UNESCO inscribed the centre in 1996 and why architecture students are sent here.

The palace and its garden

Palazzo Piccolomini is the pope's own house, and its most interesting feature is behind it rather than on the square: a Renaissance garden, laid out as part of the design, opening onto the Val d'Orcia. The building is arranged so that the private face looks at the landscape while the public face addresses the square — a deliberate separation of the civic from the contemplative. It is visited on a guided tour with an audio guide.

The town around it

Outside the square, Pienza is a ridge village: one main street along the crest with short lanes dropping off it, built in local stone, modest and unshowy. The grandeur stops at the edges of the piazza — which is itself a design decision, and the reason the square still works.