An eerie place, with murals of flayed human skins (see more-info link), scenes of torture, and a statue of Dorje Drakden in his wrathful aspect. Nechung is the former home of the State Oracle (the medium for Dorje Drakden), whom the Dalai Lamas consulted before making any important decision. The last State Oracle fled Tibet to India with the current Dalai Lama in 1959. About 1 km SE of Drepung monastery, outside Lhasa.
From the Lonely Planet Tibet guide:
"Every New Year in Lhasa until 1959, the Dalai Lama would consult the Nechung oracle on important matters of state. In preparation for the ordeal the oracle would strap on bracelets in the shape of a human eye and an elaborate headdress of feathers, so heavy that it had to be lifted onto his head by two men.
"The oracle would whip himself into a trance in an attempt to dislodge the spirit from his body. Eyewitness accounts describe how his eyeballs would swell and roll up into his sockets, and how his mouth would open wide, his tongue curl upward and his face redden. As he began to discern the future in a steel mirror the oracle answered questions in an anguished, tortured, hissing voice, which would then be translated for the court by a clerk. After the trance the oracle would faint and have to be carried away."