Wadden Sea coast, near Moddergat, Friesland, Netherlands

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—the area that is 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, brown trout and white-beaked dolphins, and it's a home or resting spot for species of birds like waders and herons.

Pictured here is the Wadden Sea coast in Friesland, Netherlands. This coast is dotted with charming fishing villages and medieval churches. Mudflat hiking is a recreational pastime here—the Dutch call it wadlopen—and the Wadden Sea is a popular destination. As the tide recedes, mud-trampers can literally walk across the seabed, squishing through the mud and wading through shallow waters. Whether you're up for a wadlopen challenge or a seal-spotting safari, there's plenty of adventure to be found here. Just don't forget your boots—things are bound to get a little messy!