The church is of Romanic origin, although only the apse, resting on a rock, dates from this period; the bell tower and part of the church were instead subject to subsequent alterations in the sixteenth to nineteenth centuries. The church has a triangular tympanum facade, flanked on the left side by the stone bell tower.
Inside it has a single nave and only the left branch of the transept. On the left wall there is a beautiful wooden crucifix carved in the fourteenth century by an unknown author.
On the right wall, at the level of the altar, we find a fresco of the sixteenth century, again by an unknown painter. At the centre
of the artwork there is the Virgin on a throne of stone; at her sides Saints: Roch, Anthony Abbot, Francis and Sebastian. Behind the group, the curtains of a pavilion, above which there are two cherubs in flight.
In the middle of the nave, on the right hand side, there is a sixteenth-century fresco attributed to the Florentine painter Donnino di Domenico. At the centre of the fresco there is the Archangel Raphael holding the hand of Tobiolo in front of St. Lorenzo. On the splay there are Seraphims with six wings, St. Sigismund and St. Roch; on the ceiling the sun and the moon mourning the death of Christ. The fresco tells the story of Tobiolo, the young son of Tobias, and his Guardian Angel (Tobias, 12).
In 2015, three restored canvases were relocated: Our Lady of the Rosary and Saints; Saint Charles Borromeo, Saint Thomas Aquinas.

The church of St. Donnino, in the hamlet of Castelmartini, today shows a triangular gable facade and a bell tower along the left transept. Inside, at a single nave, a painting of the first half of the eighteenth century representing St. Joseph with Saints Anthony Abbot and Donnino is preserved on the main altar. Behind it there is a wooden chorus, dated back to 1877. In the right branch of the transept, a carved marble altar in the typical Baroque style: with a beautiful form of the angels in the air while supporting an oval within which a small painting of the Madonna del Carmine was placed, which was unfortunately stolen in 1972.

The San Rocco’s (St. Roch’s) Church, in neo-Renaissance style, has reached its current aspect as a Latin cross after many interventions. At the back of the building, next to the apse, stands the bell tower with a square base, whose cell opens to the outside with a mullioned window on each side. The church was commissioned by the population in 1631 when the town was freed from the pestilence. In 1884 the new building was completed. The bell tower and the terrace, adorned with merlons, were started in 1911 and completed in 1929.

In the left side sandstone altar of 1641, the wild boar is represented, the symbol of the ancient community of Larciano and in the niche there is the statue of the Saint. In the niche at the right-hand side altar is a terracotta high relief of Our Lady of the Graces. On the central dome there is the fresco of St. Mary of the Assumption. Above the entrance door in the lunette a mosaic depicting the Annunciation is laid, by Gino Terreni, realised on the occasion of the centenary of the constitution of the Parish. At the same time the altar was replaced with the present one of sandstone with a central high relief depicting the Emmaus supper. The original baptismal font, the ambo, the tabernacle and the four bronze panels at the entrance door are also by the same author. Two frescoes by P. Graziani, depicting Christ Blessing and the Last Supper (1994-2004), are in the apse and the little chapel. By the same author are the panels of the Way of the Cross. In 2005 V. Spinelli donated a valuable organ built by G. Ghilardi according to the rules of the classical organ making and ideally inspired by a phonic conception attributable to the German Baroque. The fully mechanical transmission organ has 40 registers on three manuals and pedal and is located on the cantoria in front.