Mentioned in the 13th century pouillé, the parish of Ouerre, ecclesia Oirre, then had 92 parishioners. The church of Saint-Cyr-et-Sainte-Julitte is located in the centre of the village of Ouerre, halfway between Dreux and Nogent-le-Roi, on a tributary of the Eure, the Ruisseau.
Oriented, the building consists of a single nave measuring 30 m by 9 m, a vast choir and a flat chevet flanked to the north by a powerful bell tower and a sacristy built externally in 1875.
All the bays of the nave are semi-circular except for the one, remodelled, on the western façade; the two windows of the chevet were blocked, certainly in the 19th century, for the installation of the altarpiece of the choir. Above opens an oculus pierced during an extension of the church, probably contemporary with the bell tower: the latter, outside the work, forms a quadrangular tower of 5 m by 4 m at the base, 24 m high: its three floors are underlined by four string courses. The bell tower is flanked at the northwest corner by a turret housing a staircase. This regular and massive elevation, with its pointed arch bays, suggests a defensive function, perhaps dating from the 15th-16th centuries. The materials of the nave and the bell tower are homogeneous: the wall cladding is composed of flint; the buttresses, the cornices as well as the base of the bell tower are of sandstone. The roof of the nave, formerly of flat tiles, was covered with slate like the bell tower.
A paneled vault, in pointed arch, of recent construction, covers the nave and the choir. On the north side, an opening gives access to a cramped oratory built in the 19th century: it is partly taken from the lower room of the bell tower with which it communicates.
The most remarkable element of the interior decor is a set of 17th century stalls, listed as Historic Monuments, from the former Benedictine abbey church of Coulombs nearby.
In 2003, the Sauvegarde de l’Art français participated in the restoration of the exterior masonry of the nave and bell tower and in the resumption of the framework and roofing by granting aid of €8,000.