The perfectly symmetrical building is distributed over two distinct, overlapping stories, each with its independent entryway. The central chamber on the lower level has a rectangular base with its entry from a lateral door on the north side. The low ceiling consists of vaults with transverse arches, and there are two chambers, one at each end: in the west end, it is possible to enter from outside while the eastern chamber can be reached from the inside by going down five steps to a chamber that is considered to have been used for baths.

Entry to the upper level is through the northern façade by way of a double stairway that communicates through a vestibule with the central chamber. The structure of central chamber with rooms at each end occurs again, but in this case the rooms feature belvederes looking out to the east and west. The southern façade featured an open belvedere until the 17th century.

In its interior, the use of barrel vaults reinforced with transverse arches and the blind arcades of the walls is noteworthy. This space features an interesting array of symbols displayed on the sculptural reliefs of the capitals, panels and medallions. It is an original, unified sculptural program featuring animal figures –lions and pheasants–, fantastic creatures, people with walking sticks, horsemen battling with swords and the crosses with the Greek letters alpha and omega. This can be viewed as an attempt to establish a relationship between the evangelists’ message of Faith and that of Law and Justice. This exuberant decoration finds its models in goldsmithing, miniature, painting and textiles, reminding us clearly of Visigothic and Oriental styles.

The eastern belvedere held the altar with the inscription carried out by Ramiro I and his wife Paterna:

“Christ, son of God, who entered the womb of the Virgin St. Mary without human conception and emerged without corruption, who have renovated this house, which had been depleted by great old age, through your servant the glorious Prince Ramiro with his Queen consort Paterna, and, also through them, have built this altar to the glorious St. Mary at this elevated place; hear their prayer from your place in heaven and pardon their sins. May you live and reign for ever and ever. Amen. Ninth day of the calends of the July in the era 886” (23 June 848). (Translation: César García de Castro) (English translation based on the Spanish translation by Zesauro Traducciones).

The original piece was recovered and restored when the Baroque altar of the church was taken down in 1883, since the former had formed part of the masonry wall of the latter and, at the initiative of the Provincial Committee on Monuments, it was incorporated into the collection of the Archaeological Museum of Asturias.

In the 12th century, more or less, when the Church of San Miguel de Lillo lay in ruins, Santa María began to carry out its functions as a parish church, as recorded in the inventory of parishes of Bishop Gutierre of Toledo in the 14th century.

Santa María del Naranco gives name to the parish that currently performs its pastoral duties in the nearby monastery, the Monasterio de la Visitación.

At the Church of Santa María del Naranco, services are held on specific occasions.