What convinced me to go was Robin told me he saw people surfing in the park earlier. By now it was already night and nobody would be surfing but I had to see the place where people surf. It turns out there's an artificial wave produced by a pump and people surf on that wave. Too bad I didn't see this during the day with people actually surfing.
The wave people in Munich surf on.
There are other attractions in the park: a Chinese Pagoda beer house, a Japanese Tea House and Garden built to celebrate the 1972 Olympics, people sun bathing in the nude during the spring time, and more. I'll let you look that up in wikipedia.
Anyway, I didn't see much, but I'm glad I got to see the wave where people surf.