Grand Temple
The Grand Temple was the main temple built by those who came before. All information from the other temples about any way to prevent the first disaster would be send to there
"For those within the temples, each attempted to find a solution to prevent the catastrophe, with each temple "dedicated to a different method of salvation." The information collected at each temple was transmitted to a single location from which Jupiter, Juno and Minerva would "sort and sample all that was collected." The three then tested six possible solutions in succession, "each more encouraging than the last," but all six solutionsultimately failed."
Jupiter told Desmond of the Grand Master's existance in the Sync Nexus of himself, Altaïr Ibn-La'Ahad and Ezio Auditore da Firenze.
The Grand Temple is located in New York.