Arlington Hall (also called Arlington Hall Station) was a former girl's school and the headquarters of the United States Army's Signal Intelligence Service (SIS) cryptography effort during World War II. The site presently houses the George P. Shultz National Foreign Affairs Training Center, and the U.S. National Guard Readiness Center. It is located on Arlington Boulevard (U.S. Route 50) between S. Glebe Road (State Route 120) and S.