Established in 1986, the park runs from the Bay of Dollart on the Dutch border in the west to the Outer Elbe shipping channel near Cuxhaven in the east. It includes the seven East Frisian Islands, the mudflats between them, the salt marshes pressed against the mainland dikes, the dunes, the beaches, and the estuaries where freshwater rivers slow into the North Sea. The IUCN classifies the park as Category II - a national park in the strictest sense. The park administration sits in Wilhelmshaven, the naval city wedged between the Jade Bay and the open coast. The protected area is so large that the average visitor will encounter perhaps one percent of it across an entire lifetime.

On 26 June 2009, the Wadden Sea National Park was inscribed on the UNESCO World Heritage List in Seville, alongside the Dutch Wadden Sea and the Schleswig-Holstein Wadden Sea National Park. Hamburg and Denmark declined to add their stretches. The nomination was not uncontroversial. Newspapers at the time reported that some saw the UNESCO designation primarily as a marketing tool for the tourism industry - a brand that would attract more visitors without imposing meaningful new restrictions. The IUCN inspectors had visited in summer 2008, and the conservation argument was strong enough to carry the application. Whether the listing has produced more conservation or more cruise ships is a question that locals still argue about in coffee shops from Greetsiel to Dornumersiel.

The park is divided into three protection zones. Zone I, the most strictly protected, covers about 68.5 percent of the total area. You cannot wander into Zone I. Access is limited to marked paths and guided mudflat walks, year-round. The reasoning is straightforward: this is where the birds nest and rest and feed, and a misplaced footstep on a salt marsh in May can break a brood that took weeks of weather and luck to produce. The remaining zones permit a little more human activity, but the principle is the same. The Wadden Sea is not a place for casual trespass. It is a place where the rules are written in feather and shell.

Because the park is too big and too fragile to absorb visitors evenly, the management has built a network of small interpretive centers along its edges. Two large national park centers anchor the system, one in Wilhelmshaven and one in Cuxhaven. Twelve smaller information houses line the coast and the islands: Baltrum, Carolinensiel, Dangast, Dornumersiel, Fedderwardersiel, Greetsiel, Juist, Land Wursten, Norderney, Wangerooge, the lightship Borkumriff anchored off the western coast, and the central facility at Norden-Norddeich. Each one is a door into the park - a place to learn which birds are passing through this week, when the next low tide will expose which channel, and which guide is leading a Wattführung tomorrow morning. The walks themselves are the heart of the visitor experience. You step off the dike at low water, follow a leader who knows the tide tables and the soft places, and for two or three hours you cross a country that will be gone by lunchtime.

Ten to twelve million migratory birds use the Wadden Sea each year as a refueling stop on the East Atlantic Flyway. Without it, the long-distance migrations between the Arctic and West Africa would collapse. Harbor seals haul out on the sandbanks. Porpoises hunt the deeper channels. Brown shrimp, eelgrass, lugworms, cockles, mussels - the catalog of small lives runs to thousands of species, most of them invisible to a passing visitor but each of them part of the engine that makes the rest possible. The park exists because, more than once in the 20th century, that engine seemed to be running out of fuel. Setting aside 345,800 hectares of intertidal flat in 1986 was an act of belated mercy. Whether it is enough is still being tested, twice a day, by the tide.