A Mongolian largest sand dune named Khongoryn Els has an extraordinary length of 180 kilometers and 15-20 kilometers wide, reaching a height of impressive 300-400 meters. One of the best places to observe booming dunes in the southern Mongolia is Khongor Sand dunes. The sounds have been variously described as singing, whistling, squeaking, roaring and booming. To stand before an enormous, gleaming white sand dune and realize that all of this was once an ancient lake bed or coastal plain is quite astonishing. The incredible roaring sounds of distant dunes is an unforgettable experience, particularly during the quiet hours of darkness and daybreak. Starting with the wind and tumbling particles of sand and culminating in picturesque drifts of rippled sand with an entire, dynamic, living community of plants and animals; this is one of nature's most remarkable cycles, and it is truly a phenomenon of wind.  At the northern edge of the dunes on the bank of Khongor   River, there is oasis, which is rich in plantation and supports drinking   water of animal species in the region.