This composite NASA Landsat view (with north to the top) shows part of the Dariganga volcanic field. This large volcanic field is located in SE Mongolia near the border with China, which lies at the lower right. The small roughly circular features seen in this image are some of the more than 200 lava and cinder cones of Pleistocene and Holocene age that were erupted from NE-trending parallel fissures. NASA Landsat7 image (worldwind.arc.nasa.gov)