There is no standing on the green pipes. If you are standing on the green pipes, please get off them at once.”— Doctor Dala
X-66 Hexcrete archipelago is a location in Big MT in the Fallout: New Vegas add-on Old World Blues. It is directly north of the Z-38 lightwave dynamics research station, south east of the X-13 research facility and west of Z-43 innovative toxins plant.
It is made up of large hexagonal prisms sticking upright from the ground, ranging in height from shorter than the player character to several stories tall. There is also a pool of radioactive liquid which emits 1 rad per second. Two packs of night stalkers spawn to the south and east, in range to attack. In addition, its proximity to the X-13 research facility means that any robo-scorpions guarding it will attack the player when venturing north from the location.
- There does not appear to be any entrance to the structure or purpose for the location other than a fast travel point.
- Multiple Y-17 trauma override harnesses can be found roaming the area.
- The pipes surrounding the area are riddled with frag mines. Caution should be taken if deciding to walk across them.
- A cut ending to Old World Blues would have said "Goodsprings was crushed beneath bizarre hexcrete blocks that stacked to the sky." However, this still does not explain what the blocks do.