Time Out says
A large park right on Lake Zurich with a lake swimming pool.
The Richterswil Horn is a popular local park, no doubt due to its stunning location on the shores of Lake Zurich. Offering access to a range of water sports as well as beach volleyball and lake swimming in the summer months, the Horn hosts annual events including Chibli (funfairs), the Beach Party dance music festival and Cine au Lac outdoor cinema. The park also has an excellent children's playground.