DCTA Tunnel 014-B Potomac

 is part of the Metro system under the Capital Wasteland.

Notable loot

 * In the southernmost chamber (behind an underwater passage) is a D.C. Journal of Internal Medicine, guarded by a Mirelurk King and a Mirelurk (dependent on player level).

Bugs

 * the water near the Mirelurk Eggs of the Georgetown West exit sometimes glows a highly fluorescent toxic green color. This has also happened in other locations.
 * Confirmed with more details. It was normal at first pass (entered via Arlington Utility), but upon exiting to Georgetown and immediately returning the almost white glow was throughout the area. So it may be re-entering from bright daylight that causes the glitch. Due to loading, light settings may lag behind the scene by half a second.