During the 2150s, the Syrrannites used the T'Karath Sanctuary as a base to hide from the persecution of the Vulcan High Command. The Sanctuary was hidden from outside observation by geomagnetic interference inside the Forge and by holographic camouflage. In 2154, Jonathan Archer led T'Pol to the Sanctuary after being given Surak's katra by Syrran.
Shortly after, Administrator V'Las ordered that the Sanctuary be bombarded with photonic weapons, in order to destroy the Syrrannites. During the attack, Archer, T'Pol, and T'Pau were able to find the Kir'Shara in a hidden chamber and escape before much of the Sanctuary collapsed. (ENT: "The Forge", "Awakening")
By 2370, the Sanctuary had been abandoned for centuries, containing only a few decaying ruins and artifacts. The Vulcan Isolationist Movement stored their stolen piece of the Stone of Gol there, and it was where their operative Tallera assembled the entire weapon. She was subsequently captured and the Stone retrieved by Starfleet Captain Jean-Luc Picard. (TNG: "Gambit, Part II")
In the script of "The Forge", the T'Karath Sanctuary was alternatively referred to as the "T'Karath Catacombs". However, that method did not continue in the final draft scripts for subsequent episodes. In fact, the script of "Awakening" referred to the area where the Kir'Shara was located in 2154 as the sanctuary's "catacombs".
In the script of "The Forge", the "entry chambers" of the T'Karath Sanctuary were described thus; "A dark cave setting – impossible to estimate the size or layout because the only light sources are a few sharply defined thin swaths of red-tinged light from the coming dawn spiking down from what could be narrow fractures in the cave ceiling high overhead." In the script of "Awakening", the sanctuary's "common area" was described as "an ancient, dusty stronghold built into a system of slot canyons. There are a few simple, rough-hewn tables and chairs, dozens of candles, some statues and amphora, and racks of archaeological equipment. A couple of wooden ladders lead to upper levels and recesses." The "Awakening" script also described the T'Karath Sanctuary's catacombs, remarking, "Dark and dusty, cobwebs cling to the low ceilings... Vulcan mummies and other artifacts are mounted in recesses in the walls every few meters."
The script of "The Forge" established that the T'Karath Sanctuary was where Syrran discovered Surak's katra, shown in the episode's teaser. Similarly, the script of "Awakening" established that two scenes from that episode in which Archer sees and talks with Surak were meant to be in the common area of the T'Karath Sanctuary.