John Calvin Portman, Jr. (born December 4, 1924; Walhalla, South Carolina) is an American neofuturistic architect and real estate developer widely known for popularizing hotels and office buildings with multi-storied interior atria. Portman also had a particularly large impact on the cityscape of his hometown of Atlanta, with the Peachtree Center complex serving as downtown's business and tourism anchor from the 1970s onward. The Peachtree Center area includes Portman-designed Hyatt, Westin, Mandarin Oriental, and Marriott hotels.