The Prater is known not only for its amusement park—including the world famous Ferris wheel or the Liliputbahn (miniature train), very popular amongst little guests—but also for being a top green area right in the heart of the city. Since 1766, the area has little by little become what it is today. In addition to the booming restaurants and nightclubs the 2.3 sq. mi. area is free of charge and open 24 hours a day.