Although it is the hermitage of San Andrés, located on the hill overlooking the village, which has been identified with the old monastery that arose in the 10th century, it is the parish church that most clearly shows the legacy of the old Benedictine priory, as is still proclaimed by the coats of arms of Arlanza on the adjoining houses, once belonging to the monks.

This church is a single nave building with a square chancel and sections covered by groin vaults, with a Romanesque type belfry at the foot, with a massive lower body, crowned by an inverted chamfered impost that leads to the bell tower, with two semicircular arrow slits and above them another smaller one, on which there is the typical pinion-shaped finial.

The interior of the church has six fragments of relief discovered in the interior walls of the nave, in the back half, pieces decorated with four-pointed stars carved with a bevel and framed in circles, reminiscent of the Visigothic tradition.