The Wadden Sea

Twice a day the sea withdraws from the shallow bed between the Dutch mainland and the Wadden islands, exposing a landscape of sand, mud, channels and mussel banks that stretches to the horizon. It is the largest unbroken system of intertidal flats on earth, shared with Germany and Denmark, and it functions as a global service station for migratory birds, with millions passing through each year to refuel. The distinctly Dutch response to this landscape is wadlopen, mudflat walking: setting out from the mainland with a licensed guide and wading, sometimes waist-deep through channels, across the seabed to an island or in a loop back to shore. It is not a novelty stroll. Tides are unforgiving, the flats are disorienting in fog, and going without a guide is genuinely dangerous.

What you actually see

• A guided mudflat walk - the classic wadlopen crossing from Pieterburen and other villages, with licensed guides.
• Seal colonies - common and grey seals hauled out on the sandbanks, seen from boats and walks.
• Bird migration - vast flocks of waders and geese on passage in spring and autumn.
• The Wadden islands - Texel, Vlieland, Terschelling, Ameland and Schiermonnikoog, each reached by ferry.

When to go

Guided mudflat walking runs roughly May to September, timed entirely by the tide rather than the clock, so departure times shift daily. Spring and autumn are the great bird months. Winter is cold, exposed and mostly for the islands rather than the flats.

Honest expectations

Wadlopen is hard physical work: hours of walking through soft mud and cold water, sometimes chest-deep at the channels, with no shelter and no way to turn back once you commit to a crossing. Guides are legally required for good reason and people have died attempting it alone. Ferries to the islands book out in summer, especially with a car.

Nearby

Groningen city inland, and the chain of Wadden islands running east along the coast.