The Cathedral of the Holy Spirit (Catedral del Sant Esperit) is Terrassa's bishopric cathedral, sitting on the Plaça Vella in the medieval old town. The current building is largely 19th-century, but parts of the structure go back to the 15th century, and it has been the principal parish church of the town for centuries.
Inside, the most notable feature is the Christ of the Roca, a 15th-century alabaster sculpture by Llorenç Reixach that is considered one of the finest works of Catalan Gothic sculpture. The cathedral also has a small museum of liturgical objects. It is free to enter; the bell tower can sometimes be climbed by arrangement with the tourist office. The cathedral precinct hosts the city's main markets and festivals.