Atlanta's oldest--and absolutely oddest--office building.. A Wedge of Atlanta History Atlanta's infamous wrecking ball somehow missed this old triangular office building wedged into the narrow corner of Broad and Peachtree Streets. Built in 1897 and last renovated in 1987, the Flatiron stands as the oldest skyscraper in the city--all 11 stories of it. One of the few remaining historic buildings in downtown Atlanta, it's alive and well today with tenants ranging from architectural firms to law offices. Deliciously Different The peculiar building looks less like a flat iron than a tall, thin slice of triple-layered cake. The top and bottom layers are each two floors thick and separated from the middle seven layers by raised horizontal bands. Above the colonnades of the base, continuous bay windows and unbroken piers rise to the top, giving this confection a look of distinction among the modern skyscrapers looming around it.