Constructed in traditional Chinese Siheyuan style, the Yiyun House was first built by Emperor Qianlong for collecting his numerous books. It was named ‘Yiyun’ because ‘Yun’ in Chinese is a kind of aromatic plant that can protect books from moths. Burned down by the Anglo-French allied forces in 1860, it was rebuilt during Emperor Guangxu’s reign and used as the abode of his Empress Longyu.

   Yiyun House is a complex of structures including the main hall, Yiyun House, two annexes hall and corridors. The main hall is south facing, with a bat-shaped plaque hung in the middle.The owner of Yiyun House, Empress Longyu, was the last Empress of the Qing dynasty. She is best remembered signing the abdication on behalf of the child Emperor Puyi, in 1912, ending the imperial rule in China.