The Chinese fence traces a furrow in the Himalayas, its barbed wire and concrete ramparts separating Tibet from Nepal.

Here, in one of the more isolated places on Earth, China’s security cameras keep watch alongside armed sentries in guard towers.

High on the Tibetan Plateau, the Chinese have carved a 600-foot-long (182-meter) message on a hillside: "Long live the Chinese Communist Party,” inscribed in characters that can be read from orbit.