Crystal City Underground is a network of underground shops, restaurants, and walkways located beneath Crystal City, a neighborhood in Arlington, Virginia. This unique space connects various buildings and provides a convenient way for residents and visitors to navigate the area without having to go outside. The underground area spans several blocks and features a variety of amenities, including retail stores, food options, and access to public transportation. It was developed in the 1960s and has become an integral part of the community, especially during inclement weather, offering a sheltered environment for pedestrians.