A tunnel group along the railway connecting China and Laos was completed on Friday, said China Railway's Kunming bureau on Friday.
The Huangzhulin tunnel group, located in Xishuangbanna Dai Autonomous Prefecture of southwest China's Yunnan Province, is the first to be completed on the railway's China section.
The tunnel group consists of three tunnels cutting through three mountains in the city of Jinghong.
The China-Laos railway is expected to open by the end of 2021. It will slash the travel time between Kunming, the capital city of Yunnan, and Vientiane to half a day.