I have been in Siberia or the Asian part of Russia but that was almost 17 years ago in the times of USSR when it was allowed to visit only certain towns and places. I travelled by train from Moscow to Irkutsk and also visited Lake Baikal and the village Listvjanka (or something like that), then again by train to Habarovsk. I liked everything very much. Both Irkutsk and Habarovsk are nice towns and Lake Baikal beautiful.
Tuija, Nokia in Finland