List of artificial whitewater courses
The first whitewater slalom race took place on the Aar River in Switzerland in 1933. The early slalom courses were all set in natural rivers, but when whitewater slalom became an Olympic sport for the first time, at the 1972 Munich Games, the venue was the world's first concrete-channel artificial whitewater course, the Eiskanal in Augsburg.
Source: Wikipedia — List of artificial whitewater courses (CC BY-SA 4.0)