Lantern slide of Peking (Beijing) Observatory. The Beijing Ancient Observatory - a pretelescopic observatory located in Beijing, China. The revolutionary tools used within this ancient observatory were built in 1442 during the Ming Dynasty, and later amended during the Qing. As one of the oldest observatories in the world, the Beijing Ancient Observatory grounds cover an area of 10,000 square meters. The observatory itself is located on a 15 meter tall brick platform and about 40 x 40 square meters wide, an extant portion of the old Ming Dynasty era city wall that once encircled Beijing. Several of the bronze astronomical instruments are on the platform, and other armillary spheres, sundials, and other instruments are located nearby at ground level.. Part of Box 159 Pekin, slide no. 19