Hi, Kunming: museum built in cave
The China Optical History Museum was converted from the underground structure of an old factory in central Yunnan city of Kunming.
The museum houses the first optical glass melting furnace and optical processing equipment in China. This factory is China's first optical facility hailed as cradle of Chinese optical implements.
The former site of the factory has been listed as a national heritage.
Source: Xinhua Net; Trans-editing by Mo Yingyi