DescriptionOldPlanetarium - viewfromback.JPG English: The back of the Beijing Ancient Observatory. Instruments seen from left to right are: the ecliptic
(User:Piotrus) Permission (Reusing this file) Own work, copyleft: Multi-license with GFDL and Creative Commons CC-BY-SA-2.5 and older versions (2.0 and 1.0)