Animus data fragment

Animus data fragments were objects spread throughout the cities of Constantinople and Cappadocia during Desmond Miles' Animus sessions. Collecting a certain amount of fragments would unlock narrow doors in the Black Room, allowing Desmond to witness several vital moments of his life.

Trivia

 * There is a trophy/achievement called Capped for collecting all Animus data fragments. Capped.png
 * The Animus data fragments resemble the loading symbol from Assassin's Creed II and Assassin's Creed: Brotherhood.
 * There are 100 Animus data fragments spread throughout Constantinople and Cappadocia in total.
 * Collecting 25 data fragments unlocks a map of Ishak Pasha's Memoir Pages for sale in book shops.
 * Finding 30 data fragments unlocks all five parts of Desmond's Journey.
 * After collecting 50 Animus data fragments, the remaining fifty appear on the minimap.

Source

 * Assassin's Creed: Revelations