The Collégiale Saint-Jean is an 18th-century church built on a scale that reminds you Pézenas was once genuinely important — a royal administrative center and seat of the Estates of Languedoc. The interior is high and cool and contains a notable pipe organ, one of the better instruments in the region, which you will hear during services and occasional concerts. Worth stepping inside even if you are not a church enthusiast.
Attached to the broader ecclesiastical complex is the former chapel of the Pénitents Noirs, a confraternity chapel that was converted into a theater in the 19th century and is still used for performances today. Molière performed in Pézenas during the 1650s, and though this is not the exact venue he used, the continuity of theatrical life in a town this size is striking. Check the tourist office for what is on.