Pienza is the most concentrated piece of Renaissance urbanism in Italy. Pope Pius II had his hometown of Corsignano demolished and rebuilt between 1459 and 1462 according to designs by Bernardo Rossellino — a small "ideal city" with a single perfect piazza around which everything radiates. You can walk every street in twenty minutes.
The pleasure of Pienza is partly architectural and partly the walls. Stand at the back of the cathedral and the Val d'Orcia rolls away below you to Monte Amiata: cypresses, vineyards, white roads, isolated farmhouses. The same view appears on the side of every box of Tuscan pasta, but nowhere is it quite this neatly framed.