The Pulkovo Astronomical Observatory ( , official name The Central Astronomical Observatory of the Russian Academy of Sciences at Pulkovo, Гла́вная (Пу́лковская) астрономи́ческая обсервато́рия Росси́йской акаде́мии нау́к; formerly Imperial Observatory at Pulkowo ), the principal astronomical observatory of the Russian Academy of Sciences, located 19 km south of Saint Petersburg on Pulkovo Heights 75 meters above sea level.