The Augustinerkirche, a 14th-century Gothic church, is particularly renowned for the Herzgruft, an underground crypt containing the silver urns containing the hearts of 54 Habsburg rulers. The crypt is open to the public on Sundays after the 11am Mass, at which a full choir and orchestra are in attendance. Visitors are recommended to arrive around 12.30pm to give sufficient time to admire the crypt. The Augustinerkirche also offers regular evening classical concerts, and the choir can often be heard practicing. Notable for its significant history, the church has also hosted many Habsburg weddings. Further information on the concerts can be found on the website http://hochamt.augustiner.at.