Sacred sites are among the world's most visited and venerated places. They indeed offer another level of experience to its visitors and pilgrims, full of intensity, presence and, for some, higher vibration levels and consciousness. The drawback is often overcrowded places, full of tourists whose presence will ruin this privileged moment. In his forty years of pilgrimage, renowned National Geographic photographer Martin Gray has visited 160 countries and photographed hundreds of these lesser known sacred sites. He selected here his favorite hidden holy places, the result of a lifetime's quest.