Hungry Hill by Daphne Du Maurier

I tell you your mine will be in ruins and your home destroyed and your children forgotten . . . but this hill will be standing still to confound you.’ So curses Morty Donovan when ‘Copper John’ Brodrick builds his mine at Hungry Hill.

The Brodricks of Clonmere gain great wealth by harnessing the power of Hungry Hill and extracting the treasure it holds. The Donovans, the original owners of Clonmere Castle, resent the Brodricks’ success, and consider the great house and its surrounding land theirs by rights.

For generations the feud between the families has simmered, always threatening to break into violence . . .