In Assassin's Creed Revelations, which city is Ezio Auditore's principal destination?

Constantinople is Ezio Auditore’s principal destination in Assassin's Creed Revelations.

Ezio travels to Constantinople in 1511 to search for Altaïr Ibn-La'Ahad’s seals, which can unlock the fortress library at Masyaf. The city, then the capital of the Ottoman Empire, is divided into districts and becomes the center of Ezio’s final major adventure. He works with local Assassins, including Yusuf Tazim, while navigating tensions involving the Byzantine Templars and the Ottoman succession.

The game also visits Cappadocia and returns to Masyaf, so Constantinople is not the only location. It is nevertheless the principal urban setting and the base for most of Ezio’s activities. Modern Istanbul is the city’s present-day name, but Constantinople is the historically appropriate name for the game’s 1511 setting. This distinction is why “Istanbul” is not the canonical answer to this question.