Discover 100 new locations in the Appalachians and the achievement will unlock. This achievement will probably come naturally as you progress through the game and you won't have to go out of your way to get it.
You will see undiscovered location icons on your hud radar/compass as an empty outline. Once discovered, the location icon will be solid. A location will register as discovered when you move close enough to it. Several locations contain enemies. If you do not wish to engage in combat, you can sneak up close enough to the location to unlock it, and with some luck, not alering the enemies.
Once unlocked, a location will function as a fast travel or respawn point. Fast travel to or respawning at a location it will coast different amounts of caps depending on the distance to the location. Fast travel to or respawning at your own C.A.M.P. will always be free of charge so be sure to put up a camp even though you don't intend to use it.
Discovering new locations give you XP, so discovering them is a great way to net some easy XP while out exploring the Appalachians.
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