The Grand Union Canal in England is part of the British canal system. It is the principal navigable waterway between London and the Midlands. Starting in London, one arm runs to Leicester and another to Birmingham. The Birmingham canal is 137 miles (220 km) with 166 locks. The Birmingham line has a number of short branches to places including Slough, Aylesbury, Wendover, and Northampton. The Leicester line has two short arms of its own, to Market Harborough and Welford.