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 or peoples.”— Fallout description
The perk reveals all marked locations on the Pip-Boy mark, similar to the tmm console command. The markers are only revealed; the player still has to travel to the locations on foot first to unlock them as travel destinations (unlike what the Strategy Guide says). Furthermore, markers added by script, like Regulator HQ (with the Lawbringer perk) will not appear without the requisite perk.