A Chinese documentary about life on the Qinghai-Tibet Plateau will be broadcast by the National Geographic Channel, according to a contract signed by producers and the channel on Friday.

The 276-minute documentary, Roof of the World, co-produced by China Central Television (CCTV) and Beijing Five-star Legends Culture Media Co., Ltd, focuses on how people on the plateau get along with the nature and their spiritual world, said the producers.

It features footage shot under the world's biggest lake at more than five kilometers above the sea level and on a 200-meter high cliff alongside the Yarlung Zangbo River.

It took the crew 500 days to travel more than 100,000 kilometers to get the stories in Tibet, Qinghai, Sichuan, Yunnan and Gansu.

The documentary's Chinese version has already been showed on CCTV-4 and it will be the debut of its ultra high-definition (4K) version on the National Geographic Channel.

The channel is also interested in co-producing versions adapted for European and American audience, producers said.