Three huge spoil heaps, referred to as the Three Sisters, were a legacy of extensive coal mining at Garswood Hall Colliery. Begun in 1867, this was a ceaseless enterprise until 1958, nearly a century later. Postindustrial Revolution slag heaps were a common sight around the country, often blighting the landscape for years before re-greening and reclamation plans brought benefits for the people living around them. The people of Wigan were no exception; and whilst their slag heaps also became affectionally known to locals as the Wigan Alps, it took a further 20 years until these vast eye-sores metamorphosed into a glorious 44-hectare country park and woodland.