Imperial Ring Road

One of the world's most prestigious opera houses, opened in 1869 with Mozart's Don Giovanni. The building was so criticized for its design that one architect died by suicide and the other of a heart attack — neither survived to see the premiere. Allied bombing destroyed the interior in 1945; it was rebuilt and reopened in 1955 with Beethoven's Fidelio. Gustav Mahler was director from 1897 to 1907 and revolutionized operatic staging here. Standing-room tickets (Stehplatz) cost as little as 4 euros and go on sale 80 minutes before curtain — making world-class opera accessible to anyone.

Standing-room tickets are Vienna's best cultural bargain — queue starts forming 2 hours before showtime at the side entrance on Operngasse. The annual Opera Ball in February is the social event of the year.

A 5.3-kilometer boulevard circling Vienna's historic center, built between 1858 and 1865 after Emperor Franz Joseph ordered the medieval city walls demolished. It's a living catalog of historicist architecture — each building references a different era: the Parliament (Greek), the City Hall (Gothic), the University (Renaissance), the Burgtheater (Baroque). The project employed thousands of artisans and architects and bankrupted several. The ring road was designed to prevent barricade construction after the 1848 revolution — its width and openness served military as well as aesthetic purposes.

Take tram lines 1 or 2, which circle the entire Ring — it's the cheapest architectural tour in Vienna. The best stretch is between the Opera and the Votivkirche.