Explorer

Explorer is a Fallout, Fallout 2, Fallout 3 and Fallout Tactics Perk.

Fallout, Fallout 2 and Fallout Tactics

 * Requirements: Level 9
 * Ranks: 1
 * Benefit: The mark of the Explorer is to search out new and interesting locations. With this Perk, you have a greater chance of finding special places and people in random encounters.

Fallout 3

 * Requirements: Level 20
 * Ranks: 1
 * Benefit: When you choose the Explorer perk, every location in the world is revealed on your map.*

(*NOTE: You cannot fast travel directly to the locations when you take this perk.)

There is absolutely no reason to take this perk. There are many many MANY places on line that have complete maps of the fallout 3 world.