In Monteriggioni, along a stretch of the via Francigena, amidst a forest of oak trees in the village of Santa Colomba, sits the Hermitage of San Leonardo al Lago, as it was called in historic documents because of the lake in the area that dried up in the 18thcentury. The first confirmed mentions regarding a community of hermits date to 1112, but its existence seems to date an earlier period, in the 12thcentury.
In 1239, the hermitage passed to the Augustinians, and, following a papal bull in 1250, it was merged with the more famous community nearby, San Salvatore di Lecceto. The remnants of a defense wall and two towers, one round and one squared, are evidence that in 1366, the hermitage was fortified to host local residents from Santa Colomba during a period of war.
The presence of important, local religious figures, including the Blessed Agostino Novello, who spent the last years of his life here, dying in 1309, contributed to transforming San Leonardo into a pilgrimage destination.
The monastery thus experienced a period of great prosperity: the primitive, Romanesque church was enlarged and the new Gothic, single-nave church was built, divided into three bays, with a rectangular apse.
Between 1360 and 1370, the choir was entirely frescoed by the Sienese painter Lippo Vanni, with three cycles dedicated to the Virgin Mary. In the space on the ground floor, originally meant to be the refectory, another splendid fresco decorates the walls: the Crucifixion (1445), attributed to Giovanni di Paolo, painted during his early period.