It was built in the thirteenth century, and consists of a large Late Romanesque nave ended by a straight wall in which there is a small semicircular apse.
Leaning against the church, on the left side there is a small room, communicating with the sacred building through a tunnel, where lived in the second half of the thirteenth century James Papocchi.
Giacomo Papocchi, was born in Montieri, in the province of Grosseto, in 1213. In his youth he worked in local silversmith properties of the bishops of Volterra. He was charged with theft of silver worked in local foundries; according to the justice of the time, at that time administered by the Sienese, he was condemned the atrocious pain of mutilation of the right hand and left foot, thus being reduced to disability.
He asked the diocesan bishop permission to be “built into the wall,” that is to live in a small cell adjacent to the San Giacomo Apostolo church, under the religious jurisdiction of the monks of the abbey of San Galgano.
Subjected to diabolical tests, however, it reached the highest peaks of mysticism; visions and miracles swept all his life, so much so that his cult reached uninterrupted to our days.
He died full of merits, revered by his people, 28 December 1289.