Fallout 3 locations

General information
Without any of the available add-ons installed, there are 163 marked locations in Fallout 3, provided that the Lawbringer perk and the Contract Killer perk have been selected; without these there are only 161 as the Regulator HQ and the Scrapyard office are not available. The Vault 101 map marker is not counted in the Pip-Boy 3000 "locations discovered" statistic, resulting in a maximum displayed value of 162 discovered locations.

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. Of this total, only 221 are counted towards the "locations discovered" statistic in the stats section of the Pip-Boy 3000.

Settlements
Unmarked locations (not marked on the Pip-Boy) are in italic type.

Capital Wasteland
Unmarked locations (not marked on the Pip-Boy) are in italic type.

Downtown DC (Washington, DC)
Unmarked locations (not marked on the Pip-Boy) are in italic type.

Metro
Unmarked locations (not marked on the Pip-Boy) are in italic type.

Broken Steel
Adams Air Force Base can only be accessed if the add-on Broken Steel has been downloaded.

The Pitt
The Pitt can only be accessed if the add-on The Pitt has been downloaded. Unmarked locations (not marked on the Pip-Boy) are in italic type.

Point Lookout
Point Lookout can only be accessed if the add-on Point Lookout has been downloaded. Unmarked locations (not marked on the Pip-Boy) are in italic type.

Mothership Zeta
Mothership Zeta can only be accessed if the add-on Mothership Zeta has been downloaded.