Xy Guangqi house (17 Nandan rd) in front of Observatory in the park is the oldest (500 years) building in Shanghai. The house initially called ``Nanchun Huatang'' was mooved from the initial place to Guangqi park. All the district called after Xu Guangqi and his family, living here. He was one of the first chinese, who adopted Christianinty, translator of Euclid, friend of Matteo Richi. .