Vatican Vault

The Vatican Vault was a large chamber constructed by Those Who Came Before, located beneath the Sistine Chapel in the Vatican, in order to transmit a warning to Desmond Miles in the year 2012.

Entering The Vault
It appears that the only way to enter The Vault is by combining two Pieces of Eden, an Apple and the Staff, held by a chosen descendant of Those Who Came Before, who is most likely a member of the bloodline of Altaïr Ibn-La'Ahad. Recognized as "The Prophet," Ezio Auditore was able to enter The Vault by using the Staff in conjunction with the Apple of Eden. Despite attempting to use the same two Pieces of Eden, Rodrigo Borgia was unable to enter The Vault. It is likely that half human/Those Who Came Before DNA was needed to activate them, similar to Desmond activating the Apple.

Inside The Vault
The floors, walls and pillars of The Vault were covered in glyphs that only appeared to Ezio as he moved toward them for as Those Who Came Before knew, he possessed Altaïr's supernatural gift of Eagle Vision, and was therefore deemed worthy to see the images as The Prophet. It was thought by Rodrigo Borgia, the Pope at the time, that The Vault contained God himself. Unbeknown to all, The Vault instead contained a holographic projector. Minerva, who appeared through this device, explained that she was part of a highly advanced race that existed before mankind, Those Who Came Before. She explained that her race had created humans, but had soon faced rebellion thereafter. Glyphs on the wall confirmed this, showing an Egyptian hieroglyphic with one of Those Who Came Before holding a Piece of Eden as humans charged toward him with weapons.

According to Minerva, the Temples were built by "those who knew to turn away from war," presumably those who did not fight or did not want to fight in the war between the humans and Those Who Came Before. The reason for this was a devestating large solar flare, that significantly damaged the Earth and killed off most of both species. Those in the Temples worked to protect the world, and Minerva has tasked Desmond Miles (speaking to him through Ezio) with locating the other Temples to avert another cataclysm.

Minerva's speech
thumb|left|300px|Minerva's Message to Desmond

"'When we were still flesh, and our homes still whole, your kind betrayed us... We who made you. We who gave you life. We were strong but you were many, and both of us craved war. So busy were we with earthly concerns, we failed to notice the heavens, and by the time we did, the world burned until naught remained but ash. It should have ended then and there, but we built you in our own image. We built you, to survive, and so we did. Few were our numbers, your kind and mine. It took sacrifice, strength, compassion, but we rebuilt, and as life returned to the world, we endeavored to ensure this tragedy could not be repeated. But now, we are dying, and time will work against us. Truth turned into myth and legend. What we built, misunderstood. Let my words preserve the message and make a record of our loss. But let my word also bring hope. You must find the other temples, built by those who knew to turn away from war. They worked to protect us, to save us from the fire. If you can find them, if their work can be saved, so too might this world. Be quick, for time grows short, and guard against the cross, for there are many who will stand in your way."

"It is done. The message is delivered. We are gone now from this world, all of us. We can do no more... The rest is up to you, Desmond.'"

Minerva's message implies that the Temples contain some sort of assistance or research in saving the world from a repeat of the catastrophe that occurred before.