Dimminsdale is a 37 hectare geological and biological Site of Special Scientific Interest partly in Derbyshire and partly in Leicestershire. It is located east of Calke in Derbyshire. It is a Geological Conservation Review site, and an area of 23.5 hectares is owned by Severn Trent Water and managed by the Leicestershire and Rutland Wildlife Trust.
Dimminsdale has semi-natural woodland and one of the largest areas of unimproved acidic grassland in the county. Earl Ferrers' lead mine, which is located on the site, has a unique and complex mixture of minerals such as galena and zinc blende; their genesis is little understood and they provide great potential for research.
There is public access to footpaths on the nature reserve part of the site.