1145 17th Street NW
The National Geographic Society headquarters, located at 1145 Seventeenth Street Northwest in Washington, DC, is a ten-story, mid-century modern office building and exhibition space that was designed by architect Edward Durell Stone, and built between 1961 and 1963. Constructed of reinforced concrete, with an exterior of white marble, black granite, and dark glass, the building consists of a single, freestanding, rectangular block that is capped by a flat projecting roof. An exterior covered walkway, elevated several feet above street grade, also extends from the building’s first floor on all four sides. The building lot, which slightly decreases in elevation from north to south, is approximately 290 feet in length. Its width ranges from approximately 239 feet on its northern end to 228 feet at its southern termination. The lot is bounded on the north by M Street and on the south by an alley, Sumner Row. On the west, the lot is bounded by Seventeenth Street. The eastern portion of the lot consists of a landscaped plaza, which separates the headquarters from an adjacent National Geographic-owned building.