The Guoliang Tunnel is carved along the side of and through a mountain in China. The tunnel links the village of Guoliang to the outside through the Taihang Mountains. It was carved by just 13 villagers with no power tools.
At the most difficult stage, the tunnel progressed at a rate of one meter every three days. It is 1.2 kilometers (0.75 mi) long, 5 meters (16 ft) tall and 4 meters (13 ft) wide.
The tunnel opened to traffic on 1 May 1977. Its creation has turned the village into a tourist attraction. The area has also been used as a film location.