If I were able to make an open world game with a map like from the Fallout games, I'd intentionally hide something interesting way out in the out-of-bounds area as an Easter egg to mess with people and spark fan theories.

@Chameloshi: Like a small shack or house with minor or useless loot and weapons, maybe a normally unobtainable useless weapon, and a generic NPC that would say something like "I came out here so I won't have to deal with people like you".