The Terror of Blue John Gap - Locations

Locations

• Miss Allerton's farm: the place in Derbyshire where Dr. Hardcastle was sent in a futile attempt to recover from his illness. The farm is 1,420 feet (430 m) above sea level and surrounded by limestone cliffs and hills. Professor Saunderson was "not above scaring crows in those very fields."
• Blue John Gap: a mine, one of only two in the world where the beautiful and rare Blue John mineral is found. The Romans created the mine and, in the process, their shaft intersected into the great water-worn caves of the underworld.
• Underworld: Dr. Hardcastle discovers that the limestone hills are hollow: "Strike it with some gigantic hammer it would boom like a drum." Inside, he theorised, is a huge subterranean sea. The evaporation from this sea supports a forest and animal life, which entered the caves from the surface and became trapped when the caves where cut off. Since then they have evolved into the creatures Hardcastle encountered.