The idea that our planet consists of a hollow, or honeycombed, interior is not new. Some of the oldest cultures speak of civilizations inside of vast cavern-cities, within the bowels of the earth. According to certain Buddhist and Hindu traditions, secret tunnels connect Tibet with a subterranean paradise, and they call this legendary underworld Agartha. In India, this underground oasis is best known by its Sanskrit name, Shambhala, thought to mean 'place of tranquility
