Situated near an ancient medieval installation in the center of
Valdelsa, has taken for a long time advantage of its happy
position of street node in the center of Tuscany.
In the middle ages, Poggio Bonizio is described in the chronicles
of the time as one of the strongest and rich castles in Italy.
Destroyed by the Florentines around 1115 was reconstructed some decades after, with the aid of Siena, but with the defeat of the imperial army in the second half  XII century Florence got the same privileges of Siena respect to the castle. Although it had to swear loyalty to both, Poggio Bonizio cleverly exploited the rivalry and succeeded to obtain one sure autonomy. Followed an alternation of events then and after the return of the Guelfi in Florence, Poggio Bonizio returned to be again the point of harvest of the hostile strengths to the city.
In 1270 the castle was forced again to surrend to the enemy.
Of all the constructions remained only the “Fonte delle Fate” that citizens moved more distant, in the village of Marturi, the ancient center of Poggibonsi. On the road that brings to the basilica of San Lucchese, the Fonte of Vallepiatta, said of the Fairies, is today the only great architectonic huge of the impending and destroyed Poggio Bonizio.