Khongor sand dunes

This is a Mongolian largest sand dune reaching a height of 800 meter in some highest areas. The sand dunes in Sevrei sum, South Gobi aimag, are called Khongoryn Els. These dunes are 20 km wide and 100 km long. The Khongoryn River flows along the sand dunes and gives birth to oases. The sand dune change the color with each hour of one day, from yellow to silver to rise colored at dawn / sundown. This dune is considered one of the biggest dunes with it is length of 180 km and width of 3-5 km. The dunes make sound like plane engine in a windy day so it has been named as "Singing Dunes".