Located on the north portal of the transept of the Oviedo Cathedral, it was built in the 18th century, on the remains of the pre-Roman basilica of Santa María, from the 9th century. It is the pantheon chapel of the Asturian Kings.

It was ordered to be built by Bishop Tomás Reluz in 1705 and is the work of the architect Bernardo de Haces.

The pantheon of the Kings is right at the entrance of the temple, separated from the rest by some bars where the names of the kings buried there appear.

The cover is from Asturian Gothic, in which Flemish artists such as Nicolás de Bruselas and Nicolás de Bar exercised their influence.

The pilgrim apostles Saint Peter and Saint James on the right and Saint Paul and Saint Andrew on the left support the archivolts that support 22 reliefs of saints and prophets.

The mullion is presided over by a polychrome carving of the Virgen de la Leche and the tympanum features the risen Christ, flanked by two angels.

The altarpiece in the main chapel, finished in 1719, is the work of Antonio de Borja.

At the bottom of the chamber is the Royal Pantheon. With a gate from 1713, it keeps the remains of the Asturian and Leonese kings, princesses, princes and infants;

In this Pantheon we find the lid of Itacio's sarcophagus.