Nguyen An also known as Ruan An or Juan An (depending on the transliteration system), was a Ming Dynasty

Ming Dynasty

The Ming Dynasty, also Empire of the Great Ming, was the ruling dynasty of China from 1368 to 1644, following the collapse of the Mongol-led Yuan Dynasty. The Ming, "one of the greatest eras of orderly government and social stability in human history", was the last dynasty in China ruled by ethnic...

 eunuch, architect, and hydraulic specialist between the first and fifth decades of the 15th century. Born in Vietnam, he was taken as tribute from Vietnam to China and later became a eunuch and architect in service to the Chinese emperors. He, along with numerous architects, such as master designers and planners Cai Xin (蔡信), Chen Gui (陳珪), and Wu Zhong (吳中), master carpenter Kuai Xiang (蒯祥), and master mason Lu Xiang (陸祥), was an important principal designer and a chief builder of the Forbidden City

Forbidden City

The Forbidden City was the Chinese imperial palace from the Ming Dynasty to the end of the Qing Dynasty. It is located in the middle of Beijing, China, and now houses the Palace Museum...

 in Beijing.

Under the reign of Zhengtong Emperor

Zhengtong Emperor

Zhu Qizhen was an emperor of the Ming Dynasty. He ruled as the Zhengtong Emperor from 1435 to 1449, and as the Tianshun Emperor from 1457 to 1464....

, Nguyen An had a major role in the reconstruction of the wall of Beijing. He was also a hydraulic specialist, who was involved in at least three hydraulic projects and had a flawless record. He died in 1453.