<P> In the 1970s, two large circular banks were built in the Terrington Marsh area of the Wash, as part of an abortive attempt to turn the entire estuary into a fresh water reservoir . The plan failed, not least because the banks were built using mud dredged from the salt marsh, which then salinated stored fresh water . </P> <P> From 13th century the market town and seaport of Bishop's Lynn became the first member trading depot (kontor) of the Hanseatic League of ports in the Kingdom of England . During the 14th century, Bishop's Lynn ranked as the most important port in England, when sea trade with Europe was dominated by the Hanseatic League . The town still retains two former medieval Hanseatic League warehouses--Hanse House built in 1475 and Marriott's Warehouse . </P> <P> King John of England is said to have lost some of his jewels at the Wash in 1216 . According to contemporary reports, John travelled from Spalding, Lincolnshire, to Bishop's Lynn, Norfolk, but he was taken ill and decided to return . While he took the longer route by way of Wisbech, he sent his baggage train along the causeway and ford across the mouth of the Wellstream . This route was usable only at low tide; the horse - drawn wagons moved too slowly for the incoming tide, and many were lost . However, scholars cannot agree on whether the king's jewels were actually inside the baggage train, and there is evidence that his regalia were intact after the journey . </P> <P> The location of the accident is supposed to be somewhere near Sutton Bridge, on the River Nene . The name of the river changed as a result of redirection of the Great Ouse in the 17th century, and Bishop's Lynn became King's Lynn as a result of King Henry VIII's rearrangement of the Church of England . </P>

Who lost the crown jewels in the wash