Saint-Rémy church is the former chapel of the castle which was a dependency of the counts of Mortain. Only the transept remains which is fairly narrow and the choir with a flat chevet, the nave having been destroyed during the Revolution.
The tower which dominates the transept crossing, crowned by a circular spire in stone seems to be from the 12th century with window-less arcatures in the south and east faces but with later additions (loopholes and watchtowers with machicolations at the corners) stemming from the fortification of the monument during the Hundred Years War. 

Bibliography

- Dictionnaire des églises de France, Belgique, Luxembourg, Suisse, IVB, Normandie, Paris, 1968, p. 179 (notice de P. Siguret).
- Tinchebray, ancienne église Saint-Rémy, Les Siècles romans en Basse-Normandie, Art de Basse-Normandie, n° 92, printemps 1985, p. 107. 
- Juhel, V. "La chapelle Saint-Rémy de Tinchebray", Annuaire des cinq départements de la Normandie, Congrès de Tinchebray, 157e congrès, 1999, p. 8-11.