The most authentic way to experience Mongolia is to travel on horseback accompanied by nomads; explore the mountains, forest and steppes on the hardy Mongolian horses. 
Horse riding is a great way to see the region and to experience the Mongolian way of life; riding is the primary form of transport in the countryside. The horses are traditional Mongolian ponies, small by European standards, but thoroughly suited for the rugged environment. Local guides look after the horses and give you any assistance. Rides can range from a couple of hours along the lake shore to longer treks of a week or more, covering 20-30km and riding 4-5 hours a day.