The northern part of Aix-en-Provence's historic center comprises Saint-Sauveur Cathedral and the large yellow building of the thermal baths with their gardens and swimming pool. Located on the Cours Sextius, in the former Observance district, the spa was built by the city at the beginning of the 13th century on the foundations of an ancient Roman house. It has preserved a vaulted swimming pool equipped with side benches from Roman times. Listed as a spa in 1913 and operated by the Société des Thermes from 1921, Aix-en-Provence has long been renowned for its thermal waters.