Wash, the

Bay of the North Sea between Norfolk and Lincolnshire, eastern England; 24 km/15 mi long, 40 km/25 mi wide. The rivers Nene, Ouse, Welland, and Witham drain into the Wash. In 1992, 10,120 ha/25,000 acres of the mudflats, marshes, and sand banks on its shores were designated a national nature reserve.

Much of the land adjacent to the Wash has been reclaimed. King John is said to have lost his baggage and treasure while crossing it in 1216.