Montalcino is a medieval hilltop town that specializes in the production of Brunello wine. It is supposed to have some of the most beautiful views in Tuscany. It also has a bunch of great restaurants (even one with a Michelin star) and wineries to try. It is about an hour drive from Tocchi.
Siena is another medieval town to explore that is closer to Tocchi. It is about 30 minutes away and has a bunch of restaurants and bars to try as well as sights to explore. It also has hotels for guests to stay in if you don't mind being slightly farther away from the venue.
The thermal springs of Bagni di Petriolo are along a stretch of the Farma river. A distinguishing characteristic is the presence of hydrogen sulphide: this water is rich in salts and hyperthermic, with multiple therapeutic properties. People can explore the thermal baths in the national park or at various spas/hotels in the region. It is about 20 min away from Tocchi.