The swimming baths are just next to the tram 14 stop "Im Heurid". The reason I call it a gem is this cool looking water slide. And when I was cycling around there were adults using it too.
I'm heading there the next time it's a hot evening - can't wait!
Heuried has the biggest water slide in the city. Twenty years ago you had to buy tickets and a slide cost 50 Rp. The biggest slide park in Switzerland is the already mentioned Alpamare, as far as I know.