In terms of planning and engineering alone, the Washington, D.C. Metro system is architecturally significant.

There are 117 miles of track serving 91 stations in the District, Maryland and Virginia. Most of it is below ground. Most of it designed by Chicago based architect Harry Weese who relied heavily on the Brutalist style - which was popular at the time of Metro's launch in the 1970's - with a slight nod to the more traditional architecture of monumental Washington.

Weese's design sought to create familiar spaces at every station. Though each station is different, because of location and site conditions, the Metro user can easily figure out where to go upon entry based on the familiar repeating patterns of materials, lighting and signage. These patterns have been largely maintained as new stations open using new materials.

Since its opening, in 1976, Metro has received a number of awards and mentions from the architectural community. In 2007, it made the list of America's Favorite Architecture(106) as compiled by the American Institute of Architecture. Seven years later, in 2014, AIA cited the Metro system as a "design of enduring significance."

The Metro has also had an impact on the overall development of the Washington, D.C. region, lifestyles and socialization within the market.

Access to the system is a highly valuable asset in the real estate market. New stations have led to more transit oriented development projects. The Metro is a fully public system that brings different classes of people together throughout the day in a city and region that has been more segregated along racial and class lines throughout its history. And when average Americans and people from other countries visit Washington, D.C., local residents become unofficial tour guides and ambassadors.