DCRails.com
- Uses Google Maps to find the closest Metrorail stop to a given address.
- http://dcrails.com

D.C. Underground
- Information about existing subway tunnels, including those no longer in daily use. Also features information on local heavy rail structures and the U.S. Capitol building's subway.
- http://www.clouse.org/

Please Stand to the Right
- Sells T-shirts and other merchandise urging tourists to stand on the right side of Metro escalators.
- http://www.standtotheright.com/

WMATA - Metrorail System
- Maps, station information, and how to use the Washington Metro.
- http://www.wmata.com/riding/using_metro.cfm

StationMasters
- Features detailed maps and panoramic photos of all neighborhoods served by the Washington, DC Metrorail subway system.
- http://www.stationmasters.com/System_Map/system_map.html

Washington, D. C.
- Metrorail Resources page provided by the Washington Post (commercials included).
- http://www.washingtonpost.com/wp-srv/local/longterm/metro/uchoose.htm

NYCSubway.org: Washington D.C. Transit
- Gives an in-depth look at the Metrorail system, from fare collection to signal systems to station architecture. Provides historical timeline, station-by-station guided tour, photos, maps, and links to similar sites.
- http://www.nycsubway.org/us/washdc/

Building the Washington Metro
- Describes the planning, engineering, architecture, construction, and operation of the subway system in text and photos.
- http://chnm.gmu.edu/metro/