The Long Corridor was first built in 1750, when the Qianlong Emperor commissioned work to convert the area into an imperial garden. The corridor was constructed so that the emperor’s mother could enjoy a walk through the gardens protected from the elements.
Like most of the Summer Palace, the Long Corridor was severely damaged by fire which Anglo-French allied forces laid in 1860 during the Second Opium War. It was rebuilt in 1886. It is famous for its length (728 m) in conjunction with its rich painted decoration (more than 14,000 paintings).
Definitely worth a visit!