Halifax is a town in the Metropolitan Borough of Calderdale, in West Yorkshire, England. It is in the eastern foothills of the Pennines. In the 15th century, the town became an economic hub of the old West Riding of Yorkshire, primarily in woollen manufacture with the large Piece Hall square later built for trading wool in the town centre. The town was a thriving mill town during the Industrial Revolution with the Dean Clough Mill buildings a surviving landmark.