Tucked into Salzburg's Gneis district along the Almkanal, the Almwelle sits where an old lock structure called the Suchmann once diverted floodwater—in 2010 the city converted the site into a proper paddling and surfing facility. It's free to surf, the wave can be dialed up or down quickly, and that adjustability is what makes it work for everyone from first-timers to folks pushing their carving. You can surf it year-round, and summer evenings get genuinely busy, though the canal shuts down for about three weeks every September for the local Almabkehr event. Just respect the current and stay clear of the power-plant intakes if you end up swimming.