National Monument since 1976.
The church conserves its original, sandstone factory. It is composed of a single nave, a semicircular headland to the east, a porticoed portal and gallery to the south, and a tower to the northeast.

The importance of this temple is due to the existing inscription in one of its 25 corbels, located on the cornice of the porticoed gallery representing a monk with an open book in his hands and in which you can read: "+ IVLIA / NUS MA / GISTER / FECIT / ERA / MC / XV / IIII ". "Master Julianus made me in the era of 1119" (year 1081). Thus, the church can be dated between 1050 and 1081. For this reason we have not only the oldest porticoed gallery in Castile, but also the oldest romantic temples in the southern area of ​​the Douro.

It is evident that San Miguel is being built in a border and conflict zone some 50 years before being restored in the episcopal seat of Osma, by displaced teachers in the area of ​​"Extremadura" with the sole mission of building Christian temples and showing the premises in what the new technique of the moment consists of: Romanesque. Several theories have tried to explain the origin of the porticos, although the most recent in comparison with San Miguel with its closest precedent, the pre-Romanesque Church of San Miguel de la Escalada in León, which has a portico with 12 arches of Herradura. This could confirm the origin of romantic arcaded galleries. It would be a possible explanation of the sculptural decoration of its capitals and corbels.

Inside there are some late paintings representative of the Visitation, the Adoration of the Magi and the Flight to Egypt. The projects of the Cultural Project Soria Romanesque the results in 2009 allowed to bring to light the plasters of the Roman era and were discovered, at 4 meters high, the graffiti of the twelfth and thirteenth centuries, rare characters, funerary inscriptions, traces of the fingers of the masons who smoothed the plaster with their hands, crosses of consecration, accounting combs, etc.

Also during these excavations were found, in the porticoed gallery of the church, in the medieval tomb in which was found the patriarch crusade or double crossing of the twelfth century. This exceptional find is exhibited in the Museo Numantino de Soria. The pieces of wood covered with copper plates and overdorado and four colored stones. The Christ is three-dimensional highlighted by the presence of champlevé enamel (Limoges technique), coming from the workshops of Santo Domingo de Silos.

It has been restored and recently rehabilitated.