Purple Mountain Observatory Museum

The observatory the park calls 'the cradle of modern Chinese astronomy', on the mountain's third peak at about 267 m. Built in 1934, it is the first modern astronomical research institution China established on its own, and the old site is now a museum run by the scenic-area manager: five Ming and Qing instruments, the 600 mm reflector the manager says was once Asia's largest, Zhang Yuzhe's office, and the Tianbao Castle platform over the city. It is shut: closed since 2026-09-01 for conservation works scheduled to run to the end of 2027, with no reopening date announced. The cableway past it still runs.