Head to Forteresse de Miremont and learn about its role in defending the area. This structure has witnessed some interesting history in its time.
You'll have sightseeing choices galore in Mauzens-et-Miremont. Forteresse de Miremont is a great place to begin here, but there are lots of other interesting spots to visit. Parc le Bournat, Aquarium du Perigord Noir, and Golf de la Marterie are near the history-filled fortress and will round out your day nicely.