This is Grove Rake Mine near Rookhope in County Durham.It finished its life in 1999 as the last Fluorspar mine in England but had begun as far back as the medieval times as an open cast lead mine. The old decrepit buildings have seen better days. Most of the buildings roofs have collapsed or are in the process, making it a dangerous place to be if you venture inside them. The only guardians of the mine seem to be the sheep who make the buildings their shelter.