This temple stands out for its internal height, its considerable dimensions and the lack of occidental structures. Similarly, the location and superstructure of the two lateral quarters, unique in Asturian architecture of the High Middle Ages, are peculiar. Therefore, it does not belong to the usual typology of basilicas, posing doubts regarding its initial purpose.
We have no documentary or chronicle statements referring to the moment of its foundation, except for those contained in the documentary compositions of the Testament Book of Bishop Pelayo de Oviedo, from the beginnings of the 12th century, and quotes of a church of San Pedro, in the town of Naura, dating from 1078 and 1079.
The archaeological excavations carried out in the temple have made it possible to reconstruct the original floor. This is a basilica building of three naves, with four sections over semicircular arcades supported on quadrangular pillars, and triple rectangular header, with a single straight head wall. It has two lateral quarters with rectangular flooring open to the second section of the aisles and arranged at double height, which constitutes a novelty in Asturian architectural solutions. No western front part, portico or transept were foreseen.
The header chapels are currently intercommunicated by means of gaps, an exceptional circumstance in High Middle Ages Asturian architecture, and common in some Romanesque temples, leading to suspect they were opened for reformation in the Middle Ages. The supraapsidal chamber, over the central chapel, reproduces the model of that of Santullano, with a triple gap hierarchical regarding size, with the central being larger than the lateral ones.
Except for the header chapels, covered with barrel roofs, the rest of the spaces of the temple are covered with wooden carpentry. The predominant alignment is small limestone block masonry, carefully carved and arranged in horizontal rows, with ashlar in the corners, over a perimeter baseboard. The external faces are joined by means of smutted ashlar beams on the wall. In accordance with the usual Asturian system for basilicas, the openings are arranged on the walls of the central nave, over the spandrels of the arches in dividing arcades. They have a rectangular shape. The western door is the only one used at present to access the internal part, having closed off the doors opened in the aisles. These are also opened by the doors communicating with the outgoing quarters, with a rectangular floor plan and two storeys, with the upper one being open to the respective nave by means of a large gap.
There is hardly any architectural sculpture worth mentioning. The pillars of the dividing arcades, with a square cross-section, finish off in the usual moulded imposts with horizontal strips, equally serving as bases. Identical elements appear in the arches of triumph for access to the header chapels. Externally, the eastern and western façades have occidental single-roll modillions to support the sleepers of the roof, similar to those that can be seen in Santullano or San Tirso de Oviedo.
The current aspect is the result of a long restoration performed between 1952 and 1964, which included the construction of an enormous steeple, for which there are no archaeological or typological bases.
Las Regueras. Access from Trubia via the AS - 233.