The most common and grand sacrificial activity of the Mongolians is the sacrificing of Aobao. Aobao means heaps of stones. Aobao is normally set up in hills and mountains, it is a cone-shaped solid tower made of stone.A long pole is inserted on the top, fur or animal skin and cloth ribbons are tied on the pole end, rocks for incense are placedaround.
Sacrificing of Aobao is mostly heldin each June, July and August. Whensacrificing, the worshipper will take Hadas, mutton, fermented milk and dairy food to the Aobao. Hadas and sacrifices will be presented firstly and Lamas will chant Buddhist scriptures and the other people will worship on bended knees. Then, they will addstone or wicker to the Aobao and colorful silk strips and Sutra streamers. After the sacrifice, such activities as horse races, wrestling and archery will be held, the event later will develop into a Nadamu meeting.