The small trail-side shrines in the high mountains, called chortens, are also Buddhist, and often surrounded by stones carved with the Om mani padme hum incantation  Hail, jewel in the flower of the lotus. 
The small shrines were not always called chortens, this only occurred recently. 
mnli hypothesis: The small shrines were not always called chortens, this only occurred recently.  premise: The small trail-side shrines in the high mountains, called chortens, are also Buddhist, and often surrounded by stones carved with the Om mani padme hum incantation  Hail, jewel in the flower of the lotus. 