This monument is a fine example of the religious architecture of the Romanesque, Gothic, 17th century and the Rococo. The Church of Saint Mary of Airães features a Romanesque structure, oriented in longitudinal plan, with three naves, simple square chevet and a bell tower adjacent to the lateral façade of the chancel.
From the original Romanesque building, with a single nave, only the chevet remains, with its rectangular plan covered by broken barrel arch, and the central part of the main façade facing west.
This façade features a portal with an arrangement similar to other churches in the region, set in stony pentagonal structure and salient to the façade, so it can be deeper.
Worth of notice are the stepped volumes, with different roofing, either lean-to or gabled. The main façade, with a staggered nave, ends in pediment and open gabled portico, with four archivolts sitting in capitals, carved in phytomorphic motifs, devoid of decorative elements, with a shape and size denoting Gothic solutions. Yet, the decoration of the bases and plinths follows the region’s classic trend.
While corresponding to an old foundation, the Church demonstrates the acceptance of the building models and decorative solutions typical of the Romanesque, one of the most impressive characteristics of the Romanesque Architecture in the Tâmega and Sousa.
At the Church’s basing, bolstered panels of Roman typology suggest the existence of a former building from that period in the vicinity, maybe even a primitive Paleo-Christian or Suevi-Visigoth church.
Inside, as a result of successive reconstructions, the naves are separated by round arches sitting on powerful circular pillars.
In each of the naves there is a door and two windows, and on the top, gold gilding altar-pieces. The roofing consists of wood, with a curved profile.
There is a broken triumphal arch with two archivolts, sitting on columns with sculptured capital and line of ashlars, and the chancel features in the front wall a narrow window and a small sacrarium. The ceiling features a broken arch vault.