The Seven Sisters Mine (Upper Gallery) is thought to be the last remaining surface limestone mine of it’s kind left in Europe and possibly the world, making them a unique and internationally important heritage feature.
These surface entrances are key to understanding the methods of limestone extraction employed at the site in previous centuries. The pillars supporting the mine entrances contain notable patch-reef structures of high palaeontological importance and are a key feature in terms of designation of the National Nature Reserve.
A major roof collapse occurred in October 2001, which, if left unchecked, would have resulted in the loss of the Seven Sisters.
Funding from the English Partnerships Land Stabilisation Programme was secured to fill in the lower caverns and to temporarily fill the upper daylight gallery with stone to protect it from further collapse. The project was accepted as a Demonstration Project in the ODPM Constructing Excellence scheme and achieved the maximum score under the Considerate Constructor Scheme.
Further work was carried out as part of the HLF funded Ripples through Time project. Graham Worton, Borough Geologist explains how the Seven Sisters Mines were stabilised.