Makalu trekking in eastern Nepal is protected by the Makalu Barun National Park and Conservation Project. Established in 1992, it covers 2330 sq km. Among the 16 mountains in the park, it is home to Makalu, the fifth highest mountain in the world (8463m/ 27,766ft). The world's fifth highest mountain. Formerly a restricted area, it spans five major ecological zones where can be found the lush, tropical Arun Valley, dense forests or rhododendron and fir and alpine meadows that lead to the might Barun glacier. From the base camp, any one can view the spectacular Mt. Makalu. This mainly low altitude trek is centered on the Arun Valley, in eastern Nepal. The sub-tropical valley floor of the mighty Arun River is in places densely forested, contrasting with the terraced slopes higher up, which are farmed by villagers of diverse tribal groups. High pastures typify the upper slopes, which border on the Makalu-Barun National Park, an important conservation area for many threatened species. The trails rise from 850 meters (2,788ft) to 5000 meters (16,900ft) above sea level.