The lower level of the Cathedral Basilica is home to the Mosaic Museum, which contains several displays depicting the design and installation of the mosaics. The museum also contains the original Kilgen organ console, the throne used during the visit of Pope John Paul II, and a collection of historic vestments and precious objects used in the various rites of the Church.
Also located within the museum is the Cathedral crypt, were the remains of Archbishop May and Cardinals Glennon, Ritter, and Carberry are interred. The needlepoint prie-dieu kneeler on display in the crypt was created by members of the parish for use by Pope John Paul II during his 1999 visit to Saint Louis and the Cathedral Basilica.
The museum is open from 10:00 AM – 4:00 PM Monday through Saturday and 12:00 noon – 4:00 PM on Sundays. A contribution of $2 per person is requested for admission.