The Pulkovo Astronomical Observatory near St Petersburg.The Pulkovo Astronomical Observatory is the principal astronomical observatory of the Russian Academy of Sciences.It is part of the UNESCO World Heritage Site Historic Centre of Saint Petersburg.The observatory was opened in 1839.Originally, it was a brainchild of the German/Russian astronomer Friedrich Georg Wilhelm von Struve (in 1861, his son Otto Wilhelm von Struve succeeded him). Instruments, such as the 65-cm (26-inch) refractor , horizontal meridian device , a photographic polar telescope , a big zenith telescope , stellar interferometer , 2 solar telescopes, coronagraph, a big radio telescope were installed in the Observatory. Pictured: Struve-Ertel instruments