Schleswig-Holstein Wadden Sea National Park, Germany

If you think a coastline is just a line where land meets sea, the Schleswig-Holstein Wadden Sea National Park is here to change your mind.

This UNESCO World Heritage Site along Germany's North Sea coast is a place where the tides redraw the landscape twice a day.

When the tide retreats, it exposes vast mudflats, creating an ever-changing terrain that's home to an incredible ecosystem.

With an area of 4,410 square kilometres, it is also the largest national park in Germany.

It's a paradise for migratory birds like oystercatchers and red knots, seals and tiny creatures that thrive in the shifting sands.

One of the best ways to experience the park is mudflat hiking.

Guided tours let you walk across the seabed, squishing through the soft ground while learning about the creatures beneath your feet.