In Assassin's Creed, Altaïr visits Masyaf first during the game's opening mission.
Masyaf is the mountain settlement that serves as the headquarters of the Assassin Brotherhood in the game's 12th-century storyline. Altaïr Ibn-La'Ahad returns there after an unsuccessful mission at Solomon's Temple, where his actions lead to his demotion by Al Mualim, the Brotherhood's leader. The game then sends him toward three major cities: Damascus, Acre, and Jerusalem.
Masyaf is based on the real Syrian town of the same name, which is historically associated with the Nizari Ismaili community and its fortress. Assassin's Creed blends that historical setting with fictional characters and events. A common mix-up is to name Damascus, because it is the first major city where Altaïr investigates a target after his punishment; however, Masyaf is the first location shown and visited in the opening sequence.