Beijing Ancient Observatory

The Beijing Ancient Observatory sits on a nearly nine-metre slice of the old city wall southeast of the Forbidden City and was founded in 1442 under the Yongle Emperor of the Ming dynasty. Before the invention of the telescope it served to fix the positions of sun, moon and planets - the Chinese calendar depended on these measurements, and getting them wrong could cost the emperor politically. From the 17th century Jesuit astronomers such as Ferdinand Verbiest took charge and supplemented the medieval Chinese instruments with European bronze ones: equatorial armillae, theodolite, quadrant - they still stand on the platform. In 1900 the instruments were looted by German and French troops and only returned after the First World War. The observatory is now a branch of the Beijing Planetarium and a quiet stop in heavy traffic.