The Manchester Ship Canal is a 36-mile-long (58 km) inland waterway in the North West of England linking Manchester to the Irish Sea. Starting at the Mersey Estuary near Liverpool, it generally follows the original routes of the rivers Mersey and Irwell through the historic counties of Cheshire and Lancashire. Several sets of locks lift vessels about 60 feet (18 m) up to Manchester, where the canal's terminus was built.