Siberia was a vast region located on the Asian continent, in the nation-state of Russia and bordering Outer Mongolian region. Prior to the 23rd century, a meteor impacted in Siberia flattening the forest for several kilometers.
According to Judith and Garfield Reeves-Stevens novel Prime Directive, the incident was a result of benevolent cultural contamination, as a Vulcan survey ship redirected a meteor, which would have hit Western Europe and been the greatest catastrophe Earth had ever seen, so that instead it impacted in the most sparsely populated area of the planet.
Siberia was used as a sight for a network of forced labor camps, both by Tzarist Russia and the Communist Soviet Union in the 19th and 20th centuries. The Klingon penal asteroid Rura Penthe in Star Trek VI: The Undiscovered Country was mainly based on these penal camps.