The A World Of Pain The Immortals' Shack is located on the road of the ruins just in front of the New Vegas medical clinic entrance; after spawning out of the clinic, without rotating go forward, after stepping off its sidewalk, you'll step on another one then will be the road the shack is on. Going E (cardinal direction) past the ruins but before where the electric line used to be (so to its W); in the Images section should be a World Map view taken at the center of the old electrical station angled to its longest side (so the transmission towers were placed for their power lines to go through it).
A 2 stories shack which served as a home for Mlix and her partners.
The Immortals' Shack S side; in the background is a transmission tower and the white house is next to Fiend Campsite North
The Immortals' Shack w/o moving after spawning inWorld Map view which cursor is at The Immortals' Shack and is taken at the center of the old electrical station angled to its longest side†
† which the arrowhead reflect.