The Antiquities of Zhang Zhung

"The upper portion of the Tibetan Plateau, a land of large lakes, lofty peaks, interminable plains, and deep gorges, stretches north and west of Lhasa for 1500 km. Bounded by high mountain ranges on all sides and averaging 4600 m above sea level, Upper Tibet gave rise to an extraordinary civilization in antiquity. Beginning about 3000 years ago, a chain of mountaintop citadels, temples, and intricate burial complexes appeared in this vast region of some 600,000 square kilometers."

Read more: http://www.thlib.org/bellezza/