The center of Treguier is home to cultural attractions like Maison d'Ernest Renan, so you might want to stop by during your stay. If you want to experience more of the culture Treguier has to offer, head to Cathedrale Saint-Tugdual de Treguier, Kerdalo Gardens, and Jardin du Kestellic.
Seeing the sights doesn't have to break the bank. For some things to do in Treguier, you can head to landmarks like Maison d'Ernest Renan to snap some photos and explore.