Flusswelle Thun breaks on the Aare River right in the historic center of Thun, Switzerland, where a set of upper lock gates squeeze the current into two distinct standing waves. This isn't a wave to learn on — local shops are upfront that it's built for experienced surfers, so take a lesson or go with someone who already knows the lineup. Flows hold up reasonably well through spring, summer, and fall, giving Thun one of the longer surf seasons among Swiss river waves. Expect fast, technical water and plenty of foot traffic along the riverside watching you work for every ride.