The Preserver Archive was an underground installation created by the Preservers and located on Lae'nas III. Its was constructed thousands of years ago when the Preservers first began seeding the worlds of the galaxy with the basis of the Humanoid form. When most of their civilization died off, a small group of their kind decided to go into stasis and await the time when their "children" that were the developing races would form. This group contained enough members of their population to allow their species to survive when they were awakened. The underground facility was powered by an antimatter reactor that produced neutrino emissions and an Obelisk served as a monument as well as entrance into the archive. As Preserver technology was operated by sound, three consoles were needed to be activated in ascending order to create a higher pitch to activate the machine. The Archive was considered a library and place of learning as every Preserver had a genetic memory that held the collective knowledge of their species. It was overseen by the Preserver Guardian who interacted with anyone that managed to open the Archive.
This shelter remained undisturbed for thousands of years and was unknown even during the Dominion War. By 2409, knowledge of its existence came to the attention of Thot Trel of the Breen Confederacy who believed it contained an arsenal of weaponry that he intended to pillage. This brought him into conflict with the Alpha Jem'Hadar that had a base in the Lae'nas system. Eventually, the actions of Starfleet led to the awakening of the Preservers and their protection from the Breen invaders. Upon awakening, Deferi science teams studied the archives and interacted with the Preservers with the Federation hoping to learn from them of the early history of the galaxy. Some of the Preservers decided to return into stasis while others chose to interact with their "children". Starfleet personnel had hopes that the Preservers would reveal information on other ancient races such as the Iconians and Tkon Empire. (STO mission: "Cold Storage")