The Ai Pioppi restaurant, near the Dolomites in Italy, is home to an adrenaline filled Human-Powered kinetic theme park. The park was built over a 40 year period by a guy named Bruno, entrance is free if you eat at the restaurant.
Tom Scott & Paul made this video of them sampling the rides on offer, including a wall of death and a roller-coaster. The park is unattended and maybe a little too dangerous for some.
If you are planning a trip to Ai Pioppi, be sure to check whether they are open, as they are closed all winter and most weekdays.