Wadden Sea coast, near Moddergat, Friesland, Netherlands

© Ron ter Burg/Minden Picture

Mud, sea, and sky. Wadden Sea coast, Friesland, Netherlands

If you've ever dreamed of walking on water, or something close to it, the Wadden Sea is the place for you. Tracing over 300 miles along the coast of the Netherlands, Germany, and Denmark, this UNESCO World Heritage Site offers a unique landscape of tidal flats and wetlands. In fact, it is the world's largest unbroken intertidal zone—underwater at high tide and exposed at low tide—of sand and mud flats. The area is also a playground for aquatic species such as houting fish, brown trout, and white-beaked dolphins, and is home to birds like waders and herons.