Tobolsk is a town in Tyumen Oblast, Russia, located at the confluence of the Tobol and Irtysh rivers. Founded in 1587, Tobolsk is the second-oldest Russian settlement east of the Ural Mountains in Asian Russia, and was the historic capital of the Siberia region. Population: 100,352 (2021 census); 99,694 (2010 census); 92,880 (2002 census); 94,143 (1989 Soviet census).