The DCTA tunnel 014-B Potomac is part of the Metro system under the Capital Wasteland. It is inhabited by several mirelurks.
This metro system consists of a higher northeastern area with metro tracks and several stranded metros. There is a lower southwestern area with small passage ways which continue to run on underwater.
 Notable loot
DCTA tunnel 014-B Potomac appears only in Fallout 3.
- Georgetown West exit sometimes glows a highly fluorescent toxic green color.
The water near the mirelurk eggs of the
- Although normal at first pass, entering via Arlington utility, exiting to Georgetown and immediately returning results in the almost white glow 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.