Bronze Age deer stones.
The outdoor set is from the Uushigiin Uver complex, near Mörön, Khövsgöl Aimag, northern Mongolia. We were there more or less at mid-day, so the light was not the best. If you google “Uushigiin Uver” will turn up some good Flickr sets from better photographers.
The rest were taken at the Military History Museum in Ulaanbaatar, showing some of the motifs, including outlines of weapons and everyday objects.