2 hours.

According to the information on the Xiaohongshu app, Nanyang Mansion can be visited for 2 hours, and the ticket is 40 yuan per person.

Nanyang Government Office, located in the west section of Minzhu Street (called Chayuan Street in the Qing Dynasty) in Nanyang City, was the official office of the Nanyang Prefecture in the Yuan, Ming and Qing dynasties. It is the only fully preserved prefecture-level office in China and has been established as the Nanyang Prefecture Office Museum.