

Head through and facing east into the rock is an entrance - which where you can enter the Abandoned Waste Dump location to start the Bunker Buster mission. Head to the north-side of this wire fence, where there will be a gap. It'll be a location when you get close enough to it. The location itself has a wire fence surrounding a rocky outcrop. We highly recommend running into settlements along the route however, so if you do die, you can fast travel to them (at the expense of a few caps) to save you the trip later.

It's at the far east end of the map in one of the game's higher level zones, so be wary you might find resistance along the way.
