The Tribune Tower, purchased by CIM Group, sits on three acres along Chicago's Michigan Avenue. News mogul Robert R. McCormick, known as the Colonel, became president of Tribune Company in 1911. To mark the 75th anniversary of the Chicago Tribune, McCormick held an international design competition to create "the most beautiful office building in the world," with a $50,000 prize for the winner. A renowned eccentric who directed Tribune editors to use his own system of spelling, McCormick requested secret doors and passages in case the building was ever stormed. At some point when Tribune Co.