Ilimsk

thumb|right|The Spasskya Tower of the Ilimsk Ostrog in the Taltsy Museum near [[Irkutsk]] Ilimsk () was a small town in Siberia, within today's Irkutsk Oblast of Russia. The town was flooded by the Ust-Ilimsk Reservoir in the mid-1970s.

thumb|left|Ilimsk, the center of the large Ilimsky (Ilimskoi) Okrug (District) in a 1773 atlas of the world. The District occupied roughly the northern half of today's Irkutsk Oblast Ilimsk was founded in 1630 on the Ilim River, a tributary of the Angara River, as Ilimsky Ostrog (i.e., "Fort Ilim"). From here a portage ran east to the Kuta River which joins the Lena River at Ust-Kut, thereby allowing travel from the Yenisei River basin to that of the Lena River. In early times the Ilimsk Uyezd was one of the few grain-producing areas in Siberia. Around 1700 there were 280 settlements, including seven ostrogs. In 1745 there were 7,605 peasants. Much of the grain was shipped down the Lena to feed the Okhotsk Coast and other areas in eastern Siberia. Grain production shifted south as the area around Irkutsk became more settled. From 1764 to 1775 the town was the administrative center of a district (okrug) and had population of around 700 by the end of the 19th century.