The facility is hidden from public view beneath Mount Claflin.
It is featured in only one mission,
- There is an entrance behind a waterfall, next to the trails on Mount Claflin, it is behind some fake bushes which are, in fact gates. After passing under the waterfall, there is a large metal blast door.
- There is an entrance underground, off of the river tunnel under the mountain. This is the entrances used in the "Pyramid Scheme" mission.
- There is also a third way - a pair of metal doors in the side of the mountain which used to escape The Pyramid during the mission. Although these doors can be opened, and the tunnel inside accessed, the tunnel is separated from the facility by a blast door which is only open during "Pyramid Scheme".
Improvised Weapons inside include: barrel, explosive barrel, cardboard box, trashcan (metal, with lin), trashcan (plastic lined), coffee maker, twelve pack, chair (wooden), tv, monitor, chair (swivel), dvd player, keyboard, dolly.
- The Pyramid can be entered at any time throughout the game, even after the mission to destroy it.
- The textures used within the Pyramid after similar to those used in the Ultor facilities in the Red Faction series.
- It is mentioned on the radio that investigative reporter Sephren Nichols has a show about The Pyramid.
- It may refer to NORAD's Cheyenne Mountain Complex, as the facility was also built inside a mountain.
- Based on an informative announcement on the facility intercom, Eric Gryphon was responsible for the day-to-day operations at The Pyramid.