Raiders bases

Raiders live in two bases across the wasteland. One is a cave in which their main hideout, a "really secret spot," is located. The other is just a small outpost in the south, for sometimes they have some operations to do in that area.

The main base

The northern Raiders' base near Broken Hills, where you can get all the levels of the Gunsmith (Small Guns) profession.

The southern outpost

The southern Raiders' outpost near NCR. This is the first base that you will see before you complete the farmer's quest.

The Raiders' souther outpost is located near Vault 15 and is ruled by Jim Raynes. It is basically a small, not really secret, outpost where the newbies are sent to be tested. In this location you will do your first quest for the Raiders (killing Cooper). Only a few raiders stay here permanently to watch over the new members, gather supplies, or send messages to the main base.

Very similar to Fallout 1's Khans base, this outpost is only used as a small hideout: "If you've ever doing work in that area, then this is your safehouse", as Raynes tells you. He even adds: "Yeah, it's basically just a crash house for the boys if we hear about a juicy target from the Hub or Junktown. When there's nothing going on, the few of us that stay here all the time mostly terrorise homesteaders for what we need".

They might have some jobs to offer you there if you have joined the Raiders faction (Jobs not yet implemented in the game though).