Bolgar is a town and the administrative center of Spassky District in the Republic of Tatarstan, Russia, located on the left bank of the Volga R…Bolgar is a town and the administrative center of Spassky District in the Republic of Tatarstan, Russia, located on the left bank of the Volga River, 140 kilometers from Kazan. As of the 2010 Census, its population was 8,650.