unfound area?

[Darthkenobi]

i have no idea if this is a mod add in wich i honestly don't think it is however if you go to the White House and climb up the stairs to a certain point there will be a door leading to the west entrance and from there a door leading to the east entrance and in that area there will be a door leading to the presidential metro wich also leads to the presidential sub metro again i honestly think it is not modded content i think it is part of the game however i'm runing all dlc's wich i don't know if that makes much of a difference i have not explored all of the area either

[ub3rman123]

Sounds like the metro from Broken Steel. Don't know if that's supposed to be accessible prior to its quest or not.