This document provides information about a basilica-type church located in Villaviciosa, Asturias, Spain. The church was founded in 893 by King Alfonso III the Great and is an example of Asturian pre-Romanesque architectural style. It has a three-aisled floorplan without a transept, separated by four rows of semicircular brick arches supported by thick square pillars. The building is constructed of masonry reinforced with stone blocks at the corners and on the east and west facades, porch, and Chapel of Bishops.