I think the beauty of the valley really comes from the way in which agriculture dominates the landscape, yet refrains from destroying it. Just like much of the country, farms, vineyards, and olive groves dominate every significant parcel of land. Every corner of the vista is occupied by roads, farms, olive trees, or at least a row of cyprus too neatly arranged to be natural. But each element almost undulates and conforms to the contours of the land. Farm hedges go up and down hill slopes, roads run along the hill sides. Everything works to form a wholesome entity.
Although small, Pienza importance is centered around its urban design, representing the classical harmony of the ideal city of the Renaissance. The only part of the town that actually conforms to the original Renaissance plan is the main square, the church, and the two buildings that flank it. Most everything else were built after the commissioning pope died or were the few remnants of the old town of Corsignano that was torn down to make way for the new Pienza. But the effect is still out-of-this-world, with the chaos of the mish-mashed buildings leading to the relative calm and order of the main square.