Originally a Cossack garrison, Irkustsk is the nearest large city to Lake Baikal, although it is still 70km away. A trading and administrative centre of eastern Siberia, furs and ivory were sent to China, Tibet and Mongolia in exchange for silk and tea. In more recent times it is famous as the place of exile where the Decemberists of 1825 were sent after their unsuccessful attempt to topple the Tsar.

It is possible to visit the Volkonsky and Trubetskoy houses where members of the movement lived. There is also a regional museum and an art gallery. It is also well worth taking a stroll around town to admire examples of typical Siberian wooden cottages that are often carved with lacy decorative designs.