Courageous cave explorers continue to uncover hidden treasures beneath the Earth's surface. From Mammoth Cave in the USA to ...

Prehistoric Man in Mammoth Cave Some 2,000 years ago Indians went deep into the great cavern in Kentucky to mine gypsum, leaving behind them many traces of a society that was just beginning to ...

Mammoth Cave offers a variety of cave tours throughout ... and see tubular passages with delicately encrusted gypsum walls.