In winter the Naturbad Riehen natural swimming pool turns into a small sauna village with a Finnish sauna, a wood-fired rest yurt and open-air loungers. Infusions use pure essential oils, and bathers cool off in the cold natural water of the pool. Season 3 November 2026 to 6 March 2027, Tuesday to Saturday 2 pm to 9:30 pm; Thursday is women's day. Entry CHF 30 for up to 3 hours, adults only; Sundays and Mondays bookable for private groups.