In 1766, to the dismay of the aristocracy, Emperor Josef II decreed that the vast expanse of imperial parklands known as the Prater would henceforth be open to the public. East of the inner city between the Danube Canal and the Danube proper, the Prater is a public park to this day, notable for its long promenade (the Hauptallee, more than 4.5 km (3 miles) in length); the traditional amusement-park rides; a planetarium; and a small but interesting museum devoted to the Prater's long history. If you look carefully, you can discover a handful of children's rides dating from the '20s and '30s that survived the fire that consumed most of the Volksprater in 1945. The best-known attraction is the 200-foot Ferris wheel that figured so prominently in the 1949 film The Third Man. It was one of three built in Europe at the end of the 19th century (the others were in England and France, but have long since been dismantled); the wheel was badly damaged during World War II, but restored shortly thereafter. Its progress is slow and stately (a revolution takes 10 minutes), the views from its cars magnificent, particularly toward dusk.