Devils Hole is located in south-central Nevada. The walls of this predominantly subaqueous cavern are coated with dense vein calcite. Calcite is the primary mineral in metamorphic marble.
It also occurs as a vein minereal in hot springs, and in caverns as stalactites. The actual hole is filled with salt and water heated by a geo thermal spring which miners used to bathe in.
It is the ONLY home to the "pup fish", a species of blue minnow.
These fish have never been found inhibiting any place else besides Devils Hole.
Devils Hole is also where Charlie sat meditating for three whole days straight, positive that is was "the bottomless pit" the Family was searching for. The entrance to the underworld where they would hide to avoid armageddon. Bad idea if they tried it, In 1967 two divers dove down to see what the hole held.
Their bodies were never found.
thanks to our grump from pahrump for the pictures.