Église Saint-Jean-Baptiste, Historical church in Château-Gontier-sur-Mayenne, France.

Église Saint-Jean-Baptiste is a church building organized with three naves, a transept, and a hemicycle apse all united under a copper-covered roof. The interior spaces are lit by windows and contain several architectural elements arranged throughout the different sections.

Benedictine monks of Saint-Aubin Abbey in Angers built the church in the 10th century; it existed by 1100 and served as priory and parish church. A papal bull of 31 August 1452 annexed the priory to Saint-Aubin. In 1790 the eight monks were expelled and the church became a barn and Temple of Reason. A German shell set it ablaze on 19 June 1940, and restoration uncovered 11th- to 13th-century frescoes.

The church was a priory and parish church of Château-Gontier, and in 1655 donations are recorded to the confraternities of the Crown of Our Lord and of the Rosary. In 1776 relics of Saint Jane Frances de Chantal and other saints were transferred here from the Ursuline church. The 11th- to 13th-century wall paintings, hidden under plaster since the 17th century, came to light after the 1940 fire.

The church stands in the Mayenne department at Château-Gontier-sur-Mayenne, near the former castle site where the Benedictines of Saint-Aubin founded their priory. Enter from the street through the recessed arched portal of the gabled facade. Inside, the pale stone floor has a dark central strip that leads straight down the aisle to the altar.

The crypt, divided into three naves by ten squat columns of roussard sandstone with plain capitals, is the only one of its kind in the diocese. It lies beneath the choir, which repeats its shape above.