Vault 63's entrance wing is located inside a small cave in the Ash Heap near Mount Blair, the entrance of which was concealed by a one-room shack. Inside the shack were several junk items. The door across from the entrance opened onto a small balcony with additional junk items.

In 2105, following the second activation of the Vault 63 weather machine, Vault 63 suffered significant damage. A pressure build-up inside the entrance sector caused the door to blast open from the inside with such force that that it flew all the way onto the highway north of Sutton in the Forest. The exterior shack that previously hid the Vault's entrance was also completely destroyed. Much of the sector is also caved in, leaving only a few rooms past the Vault doorframe still accessible (and briefly occupied by Lost who had managed to escape because of the destruction).