During numerous expeditions in which he explored ancient underground, rock and megalithic complexes, Alexander Koltypin http://dopotopa.com, http://earthbeforeflood.com came to the conclusion that many megalithic, rock and underground rooms and halls were made for healing and rejuvenating people using vibro-acoustic methods (using what we now call Schumann resonance). Source video by Silvie Ivanova http://megaliths.org
Read more http://www.earthbeforeflood.com/archaeoacoustics_of_ancient_buildings_and_its_use.html
