Istra is a town and the administrative center of Istrinsky District in Moscow Oblast, Russia, located on the Istra River, 40 kilometers west of Mos…Istra is a town and the administrative center of Istrinsky District in Moscow Oblast, Russia, located on the Istra River, 40 kilometers west of Moscow, on the Moscow–Riga railway. Population: 35,111 ; 33,652 ; 35,046. It was previously known as Voskresenskoye, Voskresensk.