Hofburg Palace

The Hofburg Palace is a massive complex; it was once the seat of one of the largest empires in Europe. The palace was the home of the Habsburg dynasty and served as the seat of the Emperor of Austria until 1918. The complex was expanded numerous times over the years, but its earliest origins date to the 13th century. It now houses various museums, chapels, the treasury, national theater, and the world famous Spanish Riding School. It's rather crowded in the summer, as it's one of the most popular tourist destinations in the city. FYI, if you're going to see the Spanish Riding School, there are no performances in August as the stallions are moved to the breeding facility during summer months.