Tobolsk is a small Siberian town sited on a high bank of the Irtysh river down from confluence with Tobol river. Founded in 1587 by Cossacks leader Yermak it was the capital of Siberia in the olden days and one of first Russian towns here. Being prosperous town on the route from East to West with active economical and cultural life Tobolsk began to decline when the general railroad bypassed it in 1890s.
It is the only town in Siberia and one of the few in Russia which has a stone kremlin. It was built at the turn of 17th and 18th centuries. Lots of famous people passed these walls and left or didn't a trace here. The last Russian Emperor Nicholas II and his family were exiled there before being executed in 1918. By the way, the Tobolsk prison has a good reputation -- nobody has escaped it ever for all years the prison exists.