A worker paints door frames at a monastery in Nagqu.[Photo By Wang Zhuangfei / China Daily]

Medog, the last county in China unconnected to the outside world by road, was linked to the national highway network in 2013.

In 2006, a railway was opened to link Lhasa, the capital of Tibet, with neighboring Qinghai province. The line was later extended as far as Xigaze, Tibet's second-largest city.

The region is mountainous, so building roads and railways is expensive. To compensate for this, airports were built in Lhasa, Qamdo, Nyingchi, Ngari and Xigaze, and nine airlines operate 310 flights a week to 38 cities.