At the end of the 14th century, Montisi became an independent comune and so remained until 1777, when it became at the first a frazione of Trequanda, and, after various vicissitudes due to the water supply, of San Giovanni d'Asso.
Trequanda borders the following municipalities: Asciano, Pienza, Rapolano Terme, San Giovanni d'Asso, Sinalunga and Torrita di Siena and consists of the following villages: Trequanda, Castelmuzio and Petroio.
Torrita di Siena borders the following municipalities: Cortona, Montepulciano, Pienza, Sinalunga, Trequanda.