Once one of Europe’s great imperial cities, Vienna still bears the hallmarks of its glory years: opulent baroque palaces, prestigious opera houses, and high society balls held during its annual Carnival celebrations. It’s especially easy to find memorable things to do in Vienna in the historic center, a UNESCO World Heritage Site, and along the Ringstrasse. Visit architectural wonders like the Vienna Opera House and St. Stephen’s Cathedral, then indulge in a slice of Sacher torte— rich chocolate cake with a layer of apricot jam—at a classic coffee house.