It is so unbearably hot that realistically speaking the best time to go and explore is sometime after 6 pm. It also helps that most of the stores are open so it is easy to duck in and out for a bit of reprieve if a store happens to be air-conditioned and very few of them are.  San Quirico d’Orcia is an old town that suffered much during the Sienna vs Florence wars.  This garden was put in place as a repair measure to the city walls.  There is some sort of modern interpretive art exposition which made exploring more fun.