Track laying for the Chongqing-Kunming high-speed railway was completed on Saturday, after the final pair of 500-meter steel rails was laid at the Junlian Tunnel, which sits on the border between Sichuan and Yunnan provinces in southwest China.

Construction workers marked the milestone with a group photo at the tunnel site.

The completion of track laying clears a key hurdle for the upcoming commissioning of the line, a core segment of the Beijing-Kunming corridor under China's "Eight Vertical and Eight Horizontal" high-speed rail network.

Stretching roughly 700 km with a designed speed of 350 km/h, the railway links Chongqing West Station and Kunming South Station, crossing Chongqing, Sichuan, Guizhou and Yunnan.

The route cuts across the Wumeng Mountains, known for its complex geology, and features a bridge-tunnel ratio of 87.4%, bringing tough engineering challenges to the construction team. 

Once fully operational, the travel time between Chongqing and Kunming will be shortened to around 2.5 hours. Its Chongqing-Yibin section opened to traffic in 2024.

Rail authorities expect the whole line to be ready for operation in the first half of 2027. 

The new artery will strengthen connectivity between the Chengdu-Chongqing economic circle and central Yunnan urban cluster, boosting trade, travel and integrated development across southwest China.