This original postcard is from the 1933 Century Of Progress (Chicago World's Fair) which was held in Chicago. It is in excellent condition and the front features "Chicago Central Aerial Beacon". The reverse side features a postcard format, which is unused and a paragraph that says "The Chicago Central Aerial Beacon atop the Roanoke Tower, LaSalle and Madison Streets, was erected and is maintained by Greenebaum Sons Investment Company. It rises 45 feet from the roof of the tower to an elevation of 520 feet above the sidewalk, and contains 24 Neon light tubes in addition to two rotating beacon searchlights, each of 8,000,000 beam candle power. It is visible for a distance of 100 miles" and measures approx. 3 1/2" x 5 1/2".