In Assassin's Creed Origins, Siwa is Bayek's home at the beginning of the game.
Bayek is a Medjay, a protector and lawkeeper in Ptolemaic Egypt. He lives in the remote Siwa Oasis with his wife, Aya, before the game's revenge story draws him across Egypt. The opening in Siwa establishes Bayek's duties, his family life, and the political tensions that shape the plot.
The real Siwa Oasis lies in Egypt's Western Desert, close to the Libyan border. Its isolated geography and distinctive culture make it different from the large Nile Valley cities featured later in the game. Bayek eventually visits Alexandria, Memphis, Cyrene, and other regions while investigating a secret order.
Players sometimes identify Alexandria because it is one of the game's most prominent locations and is strongly connected with Cleopatra. However, Alexandria is not Bayek's home. Siwa is the location that frames his early life and starts his journey.