From the introduction:
After having journeyed through the empty desert northwest of New Vegas for near two days, you spy a large salt flat in the distance. According to the map, the abandoned facility called Area 5 is located on the southern shore of the dry lake. You carefully descend the slopes of the surrounding hills until you reach the bottom of the valley and make your way toward the lake. After walking for a short while you come to a large chain-link fence, stretching out in both directions as far as you can see. The top is crowned with barbed wire and a rusted sign warns prospective intruders about lethal voltages running through the wires. However you notice a hole has been cut in the fence, not too far from where you're standing. You go through and past the fence and eventually find yourself on the tarmac of a ruined runway. You follow the runway for a few miles and as you walk you start hearing the ominous clicking sound of your Geiger counter. In the distance you can now make out the hangars and various other buildings that make up the central complex. You pass by the destroyed power station on the way, ruined beyond repair, and as you draw closer you can see that most of the other buildings are in an alarming state of disrepair as well. Many hangars had their roofs cave in, burying aircraft the likes of which you've never seen under the debris. You make your way over to the concourse, edging past wrecked vehicles and dozens of charred corpses. You can see the main facility building ahead of you, its doors wide open...