What is the historical background of the Huangyaguan wall?

Huangyaguan was originally built over 1400 years ago in the Northern Qi Dynasty and reinforced with brick walls in the Ming Dynasty. In 1984, major repair work has been performed on over 3 kilometres of the wall including on 20 water towers and 1 water pass. It is considered to be a miniature of the Great Wall of China. Being endowed with both natural beauty and cultural interest, it has become famous as a natural beauty spot and a summer resort.