This picture from EQUITOURS website,
a travel agency offering horseback riding tours worldwide
Above is a picture of one of the deer stones which can be found in Mongolia. These stones date from the bronze age (2500-3000 years ago) and are decorated with reindeer, some of which seem to fly over the sun and moon.
You can see more photos and read more about the the deer stones on Don Croner’s World Wide Wanders blog.
The meaning of these stones is still a mystery to all who encounter them - except, perhaps, Santa.