The Prater is a sprawling public park on the island between the Danube and the Danube Canal, formerly the imperial hunting ground and opened to the public in 1766. It has two parts: the long chestnut-lined Hauptallee for walking, jogging, and cycling, and the Wurstelprater, a permanent amusement area packed with funfair rides, beer gardens, and food stalls.
The Riesenrad, the 1897 ferris wheel that appears in 'The Third Man', is the icon. It runs slowly — one rotation takes around 15 minutes — and the views from its enclosed wooden cabins reach to the Alps on a clear day. Combine it with a Bratwurst at one of the older Würstelstands nearby. U-Bahn: Praterstern.