Vault 15
As you approach the location, you'll see a small house with a possible radscorpion nearby. After killing it, descend into a cave filled with rats. Fight your way through them until you reach an elevator, which will be destroyed. Use the rope from Shaidi Sands on the elevator shaft. Descend, killing the rats along the way, and search all the boxes and shelves to find a leather jacket—your first armor.
Proceed to the next shaft and use the second rope there. Descend and you'll encounter a battle with pigrats. Kill all the rats and pick up the ammunition from the ground. As you approach what should be a passage similar to the one leading to Vault 13, where the coordinator is located, you'll see a pile of stones and human bones. You'll receive a message stating that there's no filter and the passage is blocked. You'll also receive experience points.
There's nothing more to do in this vault, so return to the surface. Completely disillusioned, talk to Ian and ask him about the best route to the Hub and Junktown . After this conversation, two new locations will appear on your world map.
See also:
Fallout 2 Walkthrough: Gecko,
Fallout 2: Vault City,
Fallout 2 Walkthrough: Arroyo