The mannerist-baroque Mausoleum of Ferdinand II was designed by Italian architect Pietro de Pomis and begun in 1614; after Pomis’ death the mausoleum was completed by Pietro Valnegro, while Johann Bernhard Fischer von Erlach chipped in with the exuberant stuccowork and frescoes inside. Ferdinand (1578–1637), his wife and his son are interred in the crypt.

Another highlight is a red-marble sarcophagus of Ferdinand’s parents, Karl II (1540–90) and Maria of Bavaria (1551–1608). Only Maria occupies the sarcophagus – Karl II lies in the Benedictine Abbey in Seckau.