First steps of Christian architecture.
Together with other cave buildings in the Upper Ebro area, this church is one of the earliest preserved manifestations of Christianity in Cantabria.
According to some studies it could date from the period of repopulation (8th-10th centuries), but there are other theories relating it to Visigothic times. Its plan consists of a single nave in the shape of an elongated rectangle. On its ceiling there is a rectangular projection, possibly the remains of a large central pillar. Its apse has a quadrangular plan, with rounded corners, covered by an imperfect oven vault. Access is through an arch of slightly more than a semicircle which almost starts at floor level. The church has a stone bench running along the inside wall of the nave, the walls of the apse and the transverse arch. The transition to the sanctuary is achieved using two steps. Its entrance, oriented towards the south, is heavily altered.