The Hofburg is a palace that couldn't quite stop growing. What began as a medieval fortress in the 1200s expanded, wing by wing, into eighteen palace wings, nineteen courtyards and around 2,600 rooms. For six centuries it housed the Habsburgs, rulers of Austria and the Holy Roman Empire.

Habsburg ceremony matched the building's scale. When an emperor died, the palace chamberlain would knock three times on the Imperial Crypt door. "Who seeks entry?" a Franciscan friar would ask. The full list of imperial titles was recited. "We know him not." Only when the chamberlain announced "a poor sinner, a son of God" was the door opened. Franz Joseph alone had 49 titles.

VoiceMap's self-guided audio tours trace this legacy through Vienna's First District, connecting the Hofburg to the Imperial Crypt, the Augustinerkirche's heart urns and the Ringstrasse that Franz Joseph built to remake the city.