The Yerebatan Cistern

The Yerebatan Cistern is a memory in Assassin's Creed: Revelations.

Description
Ezio Auditore enters a cistern underground located directly underground of the location where Niccolò Polo's old trading post. There he assassinates multiple Templar Captains commanding the excavation, to gain multiple keys letting further progress through the cistern. Ezio is able to retrieve the key by using a hidden passage.

When exits the cistern he meets up with Sofia Sorto, showing her the map of Constantinople with the locations of many rare books.

Dialogue
Ezio arrives at the underground cistern.

Ezio meets up with Sofia Sorto.

Outcome
Ezio retrieves one of Altair's Key.

Trivia
To achieve full synchronization, Ezio must not be detected.