Castlefield is an inner city area of Manchester, in North West England. The conservation area which bears its name is bounded by the River Irwell, Quay Street, Deansgate and the Chester Road. It was the site of the Roman era fort of Mamucium or Mancunium which gave its name to Manchester. It was the terminus of the Bridgewater Canal, the world's first industrial canal built in 1764, with the oldest canal warehouse opening in 1779. The world's first passenger railway terminated here in 1830, at Liverpool Road railway station and the first railway warehouse opened here in 1831.
The Rochdale Canal met the Bridgewater Canal at Castlefield in 1805 and in the 1830s they were linked with the Mersey and Irwell Navigation by two short cuts. In 1848 the two viaducts of the Manchester, South Junction and Altrincham Railway crossed the area and joined each other, two further viaducts and one mainline station Manchester Central railway station followed.
Castlefield was designated as a conservation area in 1980 and the United Kingdom's first designated Urban Heritage Park in 1982.
The name Castlefield is a short form of 'field of the castle [i.e. fort]'. As well as lending its name to the Castlefield area of Manchester, Manchester derived its name from Mamucium which meant "breast-shaped hill" in Celtic.The designation 'The Castle-in-the-field' was in use in the Middle Ages but eventually came to be abbreviated to Castlefield, as it is in use now.
An alternative to Castlefield has also been in use, i.e. Campfield, with the meaning "field of the [Roman] fort". It is found in the name of St Matthew's Church, Campfield, and Campfield Market. A further name for the area is Aldport which is Anglo-Saxon and means "the old port" ("port" once had the meaning of "trading place", not necessarily on a waterway, and "the new port" was the main site of medieval Manchester near the confluence of the rivers Irk and Irwell).