Land locked so there are no beaches but...

If you get the opportunity to swim naked in Lake Zurich, do it. I have never felt so free, the water is so soft and feels wonderful. I am fortunate to have a friend who owns a small boat kept on the Lake so we were able to venture out into this vast lake. She (my friend) rowed as sat back and relaxed, both without a stitch on. Passers on the Lake didn't care, they just looked giggled and smiled.

See picture attached - also near St.Moritz (many miles from Zurich) is the town of Scuol renown for the famous public Engadin Spa. We first went for a dip in the large indoor swimming pool where it is customary to wear bathers. Afterwards we went through to another changing area where everyone changed into nothing to use the steam rooms, saunas, freezing plunge pool, showers and outdoor spa pool.