Standing at the confluence of the
River Irwell and
River Croal the site was used around 1850-70 as a tip for toxic
alkaline waste from the production of
sodium carbonate (soda ash) by the
Leblanc process. The surface of the waste has since weathered down to
calcium carbonate, and
calcicolous vegetation has colonised the site. As natural limestone grassland does not occur in Greater Manchester, many of the species found are rare in the county. In 1936 a major breach in the now defunct
Manchester Bolton & Bury Canal occurred east of the Nob End locks; it was repaired by Watson Homes as part of the Creams Mill development. ==Habitats==