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. Major landmarks along its route include the Barton Swing Aqueduct, the only swing aqueduct in the world, and Trafford Park, the world's first planned industrial estate and still the largest in Europe.