 The SSSI consists of three separate areas; Ilkley Moor, between Ilkley and Keighley, West Yorkshire; a large area north of the Calder Valley and east of Burnley, straddling the borders of West Yorkshire, North Yorkshire and Lancashire; an area south of the Calder Valley, between Rochdale and Huddersfield, straddling the border of West Yorkshire and Greater Manchester.The SSSI has a total area of and is the largest area of unenclosed moorland in West Yorkshire.There are extensive areas of blanket bog, interspersed by species-rich flushes and mires.