bogdo mountain

age akhtubinskiy and are astrakhan baskunchak beams big bogdinobaskunchak bogdo buddhist caspian cave caves clays covered craters dome edge europe for forms funnels greater grottoes highest hollows karst lake limestones located lowland mount mountain only paleozoic pilgrims place point region relief remains reserve rich rocks russia sacred salt sandstones sedimentary singing skeletal surface terrestrial territory there triassic underground vicinity where