The Church of Mancelos features a longitudinal planimetric development, defined by a considerable differentiation of volumes, which highlights the rectangular nave, higher than the chancel and galilee, the latter with quadrangular planimetry.
Evidently breaking this longitudinal development, the bell tower, which adjoins the galilee on the south side, appearing as a vertical element, stands out within the surrounding landscape.
First, this monumental ensemble differentiates itself for integrating this massive tower, but also and mainly because it preserves the galilee bordering the main façade, thus sheltering the portal.
The galilee stands as an extremely simple body, torn by a slightly broken arch, allowing access to the inside and whose gable is interrupted by a niche that once would have housed an image.
Given the difference in height between the galilee and the Church's façade, it is possible to see the gable of the latter. Here we gaze upon the same set merlons adorning the galilee (and which remember the contour of Gothic cantilevers), as well as the existence of a narrow crevice which allows the entrance of light in the nave. In the gable angle, a Baroque-style terminal cross.
The Church's main portal with its four archivolts, slightly broken, which rest on elegant capitals where the sculpture, of fine design, attaches to the basket, evidence of the approaching Gothic.
Based on the model created by the volutes of the Corinthian capitals and botanic motifs, with little relief, which create certain homogeneity to the ensemble, despite the compositional differences between the various capitals. Elaborated imposts, with rounded off elements, whose monumentality is enhanced by the dihedral logs in the archivolts.
The surrounding arch shows us a decorated modinature with threaded geometric motifs. The tympanum is supported by two corbels where two figures, of atlantean-style, one female, one male, were carved.
Adjacent to the galilee, the tower proudly boasts its apparatus of medieval cut composed of ashlars of several sizes. It is topped by a double bell on the main façade, sitting on a cornice and featuring a classicizing language, outcome of an intervention occurred between the 17th and 18th centuries.
In the rear and side façades, a series of merlons of pyramidal profile, alluding to the military traits intended for this type of construction. The access to the interior of the tower is made through a round portal, cut by a lintel, which, in its axis, features a narrow crevice and a rectangular window.
Regarding the Church, its apparel can be described as irregular, with its different sized ashlars. In some of them, the initials can still be identified, evidence of the late nature of the Mancelos edification.
In addition to sections of Romanesque vestments still visible on the side façades, a set of smooth modillions, whose shape is characteristic of the close cantilevers of wooden beams, stand out.
On both façades, two rectangular glass panes, characteristically modern, were torn in the Romanesque vestments, for better lighting of the nave's interior. On the south side, halfway up the nave, a series of cantilevers hints out the existence of a porched structure. Also here, a straight lintel door allows access to the inside of the nave.
We must not forget that a cloister once existed on this side. It is, therefore, for this reason that we must understand the location of the arcosolium that houses sepulchral arch, opening at floor level.
In 1944, Armando de Mattos mentioned this tomb for the first time, with a zoomorphic representation. The author of the Guide to Portugal alludes to the three curious symbols that appear next to a figurative medallion: a cross and two equestrian figures. In turn, Mario Barroca streamlined this sarcophagus in the family of those with simple motifs.
Also, in the tower, a perfect round communication arch was opened to allow access to the cloister. A study on the sacristy's façade shows us the presence of three broken arches, which are now covered, that allow us to guess the adaptation of an older space to the new functions.
To this also contributes the existence of a cornice supported by modillions identical to those in the nave. A set of cantilevers placed in the vestment, on the level immediately above the arches, allows us to confirm this possibility. What kind of space would that be? A former sacristy or even a chapter room? Considering the fact that it is built on masonry, it would certainly be one of the noblest spaces of monastic life. Which one, we cannot say.
The adaptation of this space to a sacristy would have occurred sometime during the Modern Period as indicated by the shape of the porthole, with a quatrefoil design, and of the niche opened in the central arch. In the top arches, straight lintel doors, surmounted by circular oculi, were open. We believe this intervention to be contemporary of the one which designed the bell which finishes the tower.
On the north side of the nave, we highlight several scars on the outer vestment, reflecting the various transformations to which the building was submitted.
Closed by a wooden barrel vault, the nave of the Church of Mancelos is extremely sober, with its vestments in granite, fully visible, where crevices of an evident Romanesque flavour cohabit with large windows characteristic of Modern Age.
Topped by a crevice, the triumphal arch remains as a trace of Romanesque times. Composed of two slightly broken archivolts, without any ornamental elements, it features, however, pierced capitals. Over these, an impost identical to the one in the main portal.
In the nave, close to the portal, to the left as one enters, the granite font. It does not feature any decorative element besides the ring which delineates the upper part of the base that supports the bowl, protected by a timber guard.