Barricades of sandbags erected to protect the entrance of Odessa National Academic Theatre of Opera and Ballet. The third largest city in Ukraine located in the south of the country, Odessa is the main naval base of the Ukrainian Navy and the administrative center of the Odessa region. The city, standing on the shore of the Odessa Gulf of the Black Sea, is the largest commercial sea port of Ukraine. (Photo by Rick Mave / SOPA Images/Sipa USA)