Milton Keynes is a large town in South East England. It is also the principal town of the Borough of Milton Keynes, itself part of ceremonial Buckinghamshire. It took its name from the existing village of Milton Keynes, a few miles east of the planned city centre. Uniquely for the United Kingdom, the urban form uses a 1 km grid for the top level of street hierarchy: the local form of most districts is more conventional. There are also 13 villages, many of which are mentioned in the Domesday Book. Milton Keynes' wonderful parks and waterways provide a landscape and environment many towns and cities would envy. Some are used for leisure purposes such as Caldecotte, used for sailing, and Willen, which is also used for water sports and has the longest cable-tow water skiing circuit in Europe. Others are preserved for wildlife and to provide oases of peace and tranquillity. The Grand Union Canal, which meanders through the town, provides a further valuable leisure facility.