In Assassin's Creed Revelations, Ezio visits Constantinople while searching for Altaïr's Masyaf keys.
The game follows Ezio after the events of Assassin's Creed: Brotherhood. He travels to Constantinople, the capital of the Byzantine Empire, where he becomes involved with local Assassins and investigates a set of keys connected to Altaïr's legacy. The keys unlock a vault beneath Masyaf, the historic Assassin stronghold.
Constantinople is the game's principal setting and is divided into districts with different political and cultural identities. Ezio works with characters including Yusuf Tazim and interacts with the Ottoman succession struggle involving Prince Suleiman. The story connects Ezio's final adventure with Altaïr's earlier life through memories stored in the keys.
Cairo, Jerusalem, and Alexandria are historically important cities in the broader Assassin's Creed universe, but they are not the principal city Ezio visits in this game. The modern-day framing story also follows Desmond Miles.