Employees work at a construction site of Ban Ka No. 1 Tunnel near the Luang Prabang Ancient Town, some 220 km north of the Lao capital Vientiane, Nov. 8, 2019. China-Laos railway tunnels' construction has been continuing to make lots of breakthroughs as one more major tunnel was drilled through on Friday in the tropical mountains of northern Laos. A Chinese railway engineering company, namely China Railway No. 8 Engineering Group (CREC-8), on Friday bored Ban Ka No. 1 Tunnel near the ancient Lao capital of Luang Prabang, some 220 km north of capital Vientiane. This marks another important milestone in the tunnel construction of the China-Laos railway. With a length of 4,585 meters, it is the second longest tunnel on the rarely-inhabited peninsula area half-circled by the Mekong River. What's more, the Ban Ka No. 1 Tunnel has to pass through unfavorable geology, creating lots of difficulties to the Chinese engineering company, CREC-8. It is listed as a high-risk, difficult and bottle-neck project for the China-Laos railway construction. The China-Laos Railway project started in December 2016 and is scheduled to be completed and opened to traffic in December 2021. (Photo by Kaikeo Saiyasane/Xinhua)