Fallout 3 locations

General information
Without any add-ons installed, there are 163 marked locations in Fallout 3 provided you have the Lawbringer perk; without it there are only 162 as the Regulator HQ is not available. It should also be noted that the Vault 101 map marker is not counted in the Pip-Boy 3000 "discovered locations" statistic, resulting of a maximum displayed value of 162 discovered locations (161 without Lawbringer).

Operation: Anchorage, The Pitt, Broken Steel, Point Lookout, and Mothership Zeta add a total of 10 additional marked locations to the Capital Wasteland map and 52 more on separate world maps, coming to a grand total of 225 marked locations (224 without Lawbringer). Of this total, only 221 (220 without Lawbringer) are counted towards the "discovered locations" statistic in the Pip-Boy 3000.

Capital Wasteland

 * Note: Unmarked locations are denoted in italics.

Downtown DC (Washington, DC)

 * Note: Unmarked locations are denoted in italics.

Adams Air Force Base
Adams Air Force Base can only be accessed if you have the add-on Broken Steel.
 * Adams Storage Facility
 * Air Control Tower
 * Mobile Base Crawler

The Pitt
The Pitt can only be accessed if you have the add-on The Pitt.

Point Lookout
Point Lookout can only be accessed if you have the add-on Point Lookout.

Mothership Zeta
Mothership Zeta can only be accessed if you have the add-on Mothership Zeta.