Vatican Vault
The Vault is one of the "Temples" left by "those who knew to avoid war" , but their exact purpose is still under speculation. Minerva's message is that the Vault's contain some sort of assistance or research in staving of a repeat of the Catastrophe that has occured before.
It appears that only a combination of different Pieces of Eden can open it, and are built to only allow specific people to enter, such as Ezio, who was named a "prophet." In Assassin's Creed 2 Ezio enters the vault under the Vatican and opens the Vault door by holding the staff which has a Piece of Eden attached to it. In the Vatican vault there are images on the wall that only appear when Ezio comes near them detailing other Vault's locations; this is the true "data" of Minerva's genetic transmission. We can clearly see a step pyramid so there's the possibility of a Vault in Mesoamerica or a ziggurat of Mesopotamia.
(Please list what happens to Ezio in the Vault and what Minerva's Message is)