Irkutsk is a major city in Siberia and often considered the unofficial capital of Eastern Siberia. It is situated on the Trans-Siberian Railway and it is certainly worth a stop-off in this Historical City of Russia. If visiting Irkutsk you should also definitely take the opportunity to visit Lake Baikal. The easiest way to do this is to visit nearby Listvyanka, but the more adventurous can also travel from Irkutsk to Olkhon Island in the middle of Baikal.