The Wadden Sea mudflats on Norderney's southern coast are revealed at low tide, exposing several kilometres of grey-brown sediment that is one of the most productive ecosystems in Europe. Guided mudflat walks (Wattwanderungen) depart from the island regularly — most are led by certified guides who can point out the lugworm casts, razor clams, cockles, and shorebirds that make the mudflats their home.
The walks typically last two to three hours and involve wading through shallow water and soft mud, so bring old shoes and expect to get thoroughly filthy. Children love it. The experience of being out on the open mudflats — with the island retreating behind you and nothing but flat grey landscape in every direction — is genuinely strange and memorable.