The Guoliang Tunnel in Taihang mountains (China) has been built by villagers themselves, which is an inspiring story in itself. Before 1972, the path chiseled into the rock used to be the only access linking the village with the outside world. Then the villagers decided to dig a tunnel through the rocky cliff.
The wall of the tunnel is uneven and there are more than 30 "windows" of different sizes and shapes. Some windows are round and some are square, and they range from dozens of meters long to standard-window-size. It is frightening to look down from the windows, where strange rocks hanging form the sheer cliff above and a seemingly bottomless pit lying below. A village, opposite the tunnel, appears to hang on the precipice.
