Gehenna base is the center of operations and research for the Pantheon project. Located deep within the Appalachian Mountains of rural northern Virginia, research site Gehenna is a large, secure research facility where the majority of the American Manipulator experiments and training were conducted.

The site at which Gehenna base resides today was chosen due to its inaccessability to the outside world, reachable only by a swerving, wooded dirt trail. The site consists of mostly old growth woods, several small ponds, and a sizeable Victorian style mansion, located near the center of the entire compound. It is believed that Dr. Dirac had chosen the site personally, as it was originally a hunting ground used by him and his father.

A handful of ranger towers dot the perimeter, along with a 12-foot high electrified fence, which terminates near the only road leading into (or out of) the estate. The road itself consists of a series of guard posts and electrified fences leading up to a hidden valley, which contains the operations center. The operations center appears as an enormous concrete and steel disc, bisected by an imposing tower of similar construction, drawing comparisons to a sun dial. The Director of Operations, General Graves, has his office located at the top of the bisecting tower. Within the the disc, are a series of mundane offices, hospital rooms, barracks and training centers.

The mansion, which is often referred to as Gehenna Proper, was once known as [REDACTED] and began as a hunting lodge for privileged members of [REDACTED]. It functioned in this capacity for nearly a century until the summer of 1970, when it was requisitioned as part of the original Witness trials conducted by the CIA. In 1971, the first Manipulator emerged from the Witness trials, and was studied at Gehenna.

Gehenna continued to be the nexus of the American Manipulator experiments, and would later host the evolution of the Witness trials, the Pantheon project. From Gehenna, American Manipulators would train, deploy, and refit in preparation for missions around the world.

In 2009, operations at Gehenna ceased, and the Pantheon project was dismantled. Currently, Gehenna is abandoned and nothing visible remains which would indicate its previous connection to the US Government, with the exception of a series of extremely well hidden blast-doors, located at the bottom most portion of the mansion.

 However, below all this, is the experimental, partially-substantial computer system, Abbadon, which is used to oversee Pantheon operations abroad. Deeper still, are a series of medical bays and isolation chambers belonging to the research division of Pantheon, who continue to push the boundaries of what we know of XS6 and the Tradesmen, in addition to unraveling the mysteries of their guest, the Higher Man.