All spiritual traditions have used Darkness Techniques in the pursuit of enlightenment. In Europe, the dark room often appeared in underground form as a network of tunnels, in Egypt as the Pyramids, in Rome as the catacombs, and by the Essenes, near the Dead Sea in Israel, as caves. In the Taoist tradition caves have been used throughout the ages for higher level practices. In the Tao, the cave, the Immortal Mountain, the Wu San, represents the Perfect Inner Alchemy Chamber. Meditating and fasting in the cave is the final journey of spiritual work. The caves are the Earth Mother and its energy lines. Like the hollow bones, caves contain the earliest information of life stored inside the Earth. Caves contain the vital essence of the Earth Power. The Tao says: 'When you go into the dark and this becomes total, the Darkness soon turns into light.'