X-66 Hexcrete archipelago is a location in the 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 testing 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 to several stories tall. There is also a pool of radioactive liquid which deals 1 rads per second. Two packs of night stalkers spawn to the south and east, in range to attack any player. Also, its proximity to the X-13 research facility means that any robo-scorpions guarding it will attack you if you venture north from this 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 harness' 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.