Sea dyke

The sea dyke at Noordpolderzijl is one of the most striking pieces of coastal landscape in the province of Groningen, on the Wadden Sea in the far north of the Netherlands. It is a long grass-covered earthen embankment that protects the low-lying polders behind it from the tides, and the place is also a point where visitors can step out of the farmland and into one of the largest tidal wetlands in the world. The sky here is huge, the horizon flat, and the wind and the light change by the hour.

The name gives some information. A zijl is an old word for a sluice, and Noordpolderzijl is a small harbour and sluice complex where water from the polder drains into the sea at low tide, closing when the water rises. The system of dikes, sluices and pumps is the product of centuries of effort to reclaim land from the sea, and the dikes were raised many times after floods. In Groningen, the Christmas flood of 1717 was one of the great disasters, killing thousands of people, and it is remembered as a turning point in how the dikes were built.

The dike offers a good walk. A path runs along the top, with views of the mud flats on one side and the fields on the other, and in good weather you can see for miles. On the seaward side, salt marshes stretch out, covered in low plants that turn red and purple in late summer, and they are a haven for birds. Waders, geese and ducks feed in the mud, and seals can sometimes be seen in the distance. The Wadden Sea is a UNESCO World Heritage Site, and its tides create a landscape that is different at every hour.

Mudflat walking, called wadlopen, is a popular activity on the Groningen coast, with guided tours across the sea bed at low tide, and some groups start near here. It must never be attempted without a qualified guide, as the tide can return quickly. A cafe near the harbour offers refreshments, and the area is part of long-distance cycling and walking routes.

The dike suits walkers, cyclists, birdwatchers and photographers, and it is at its best on clear, windy days. Bring windproof clothing and binoculars, and check tide times if you plan to explore the salt marsh.