The narrow main street that bisects Pienza east to west. Named for the Renaissance architect who designed the cathedral piazza, it is lined with the workshops, restaurants and (especially) the cheese shops that make up most of the town's commerce.
A walk from one end of the corso to the other takes ten minutes if no one is in the way. At the western end the street opens onto the cathedral piazza; the eastern end runs out at the Porta al Murello, where the road drops away towards Bagno Vignoni. The medieval shopfronts are mostly fifteenth-century, contemporary with Pius II's reconstruction.