This is the most important Romanesque building in the Municipality of Teo and one of the oldest Augustinian monasteries in Galicia.

It is located in the hamlet of Mosteiro (a toponym that recalls the long-disappeared monastery) in the middle of a small valley crossed by the Tarrío Stream. It is a simple temple, with an entirely Romanesque structural base.

It has an almost quadrangular apse, thick buttresses, and a unique nave with a rectangular floor plan. 

From a documentary perspective, the monastery of Santa María de Lampai is, according to the researcher, Francisco Javier Pérez Rodríguez, one of the oldest Augustinian monasteries in Galicia, although there is very little documentation on this small monastery. 

Lastly, it is worth noting that very close to the church are the three marker stones of the old Reserve of Lampai – Pedrouso,dating back to 1156. An ancient tract of land given by Alfonso VII to one of his knights, Sancho Eanes.