Inside the Sanctuary of Our Lady of O Corpiño, the oldest building is clearly revealed, made of granite ashlar, corresponding to the part of the feet of the temple, the reform of the s. XIX makes the cut of the stone regular, giving a much more homogeneous and aesthetic appearance in the area of the transept and the arches for access to the side chapels. All of this is covered by a barrel vault roof in the central nave, lined with transverse arches. The cruise is covered by a half-orange vault and a lantern on pendentives.
The presbytery is covered by a beautiful groin vault ornamented with beautiful plant-like wall paintings in the form of scrolls, divided into four parts, framing different anagrams and scriptural symbols.