This unusual former observatory is mounted on the battlements of a watchtower lying along the line of the old Ming City Wall and originally dates back to Kublai Khan’s days, when it lay north of the present site. Kublai, like later Ming and Qing emperors, relied heavily on astrologers to plan military endeavours. The present observatory – the only surviving example of several constructed during the Jin, Yuan, Ming and Qing dynasties – was built between 1437 and 1446 to facilitate both astrological predictions and seafaring navigation.
At ground level is a pleasant courtyard flanked by halls housing displays (with limited English captions). Also within the courtyard is an armillary sphere dating to 1439, supported by four dragons.
Clamber the steps to the roof of the watchtower to admire a mind-boggling array of Jesuit-designed astronomical instruments, embellished with sculptured bronze dragons and other Chinese flourishes – a kind of East and West astronomical fusion.