Austria’s Green Lake is one of those places that really surprises you. Most of the year, it’s just a regular green park, but come spring, the snow and glaciers start melting, and the whole area floods. The water can rise by 4-5 meters (13-16 feet), and sometimes even up to 8 meters (26 feet), transforming the park into an underwater wonderland. What’s wild is that visibility stays crystal clear, reaching 30 meters or more, so you can still see benches, paths, and even flower beds all submerged beneath the water!