Flooded Metro (exterior)

 shows up on the Pip Boy World Map in two places:


 * The Flooded Metro marker up by Arlington Cemetery (and a short walk from the Anchorage Memorial) is blocked by debris when going down the entrance ramp, but a door on the right takes you through offices and then maintenance tunnels which come out on tracks next to some stairs which go up to the Arlington Cemetery.


 * The Flooded Metro near the Southern border of the map is West of Arlington Library (halfway to the Nuka-Cola Plant) and across the street (North) from a raider camp. This metro is mainly caved in, and is a maze of utility tunnels and shafts filled with Mirelurks of all types. Heavy firepower may be necessary.

Notable Loot

 * When entering from the south (not Mason District South!), following the tunnel up right, the first room has a Guns and Bullets behind a transformer, near a skeletal corpse. In the same spot is also a Scoped .44 Magnum and some ammunition.
 * A Pulowski Chamber outside the metro near the south entrance (not Mason District South) contains a Chinese Army: Special Ops Training Manual
 * Near a shaft close to the Mason District, through a tunnel to the east, is a booby-trapped chamber (A). On a barrel in this chamber is The Shocker with instructions. The chamber contains some other weapons and ammo as well as a Nuka-Cola Quantum.
 * In an egg chamber down a staircase-lined square pit, ankle-deep in water, there is a gun case with a random weapon (Laser Rifle and Microfusion Cells, etc).

Bugs

 * The lower level of the Flooded Metro filled with mirelurks has been known to glitch heavily on the Xbox 360 version, literally causing Mirelurks to rise up through the floor at random. It is unknown what causes this, but for example, if a Mirelurk is below you, the Mirelurk will sometimes (especially if it is attempting to get by a barrier) suddenly appear on the level that the Lone Wanderer is on.  This can happen frequently.
 * Doorways can become unpassable, perhaps due to objects on lower floors clipping through the floor and obstructing your path. If this happens, try saving the game, plant a Frag Mine or two (conveniently, there are several available in the Flooded Metro), and shoot them from a safe distance. (Bug encountered on Xbox 360.)