For over a century, swimming in central Berlin’s Spree River has been banned due to hygiene concerns. Now, campaigners from Flussbad Berlin are challenging that rule — not with placards, but with paddles. As urban waterways in cities like Paris and New York open to swimmers, Berliners argue it’s time their city followed suit. With improved water quality and climate change driving the need for urban cooling, could the capital finally lift the ban?