Located behind Cafe 13 at the corner of 13th & ArapahoeThe Colorado National Guard Armory was built in 1913. The building served as the armory, quarters, mess hall, and auditorium for the Guard's Company A of Engineers.Over the years, the building has served as Golden's post office, barracks, hotel, and student housing. It was an emergency hospital during the influenza epidemic of 1918, then the headquarters of the Civil Works Administration following the Great Depression.Originally designed for brick construction, local cobblestones were instead used to save costs. An incredible 6,600 tons of stone were hauled from Clear Creek to build the structure. Today, the Armory is still the largest cobblestone building in the United States.