An Isu map is a map projected by or derived from Precursor relics or knowledge. Many pinpoint the locations of Isu temples and artifacts.
Apple of Eden 2
This map was projected by the Apple of Eden 2 after Assassin Altaïr Ibn-La'Ahad killed his Mentor Al Mualim. It was later seen by Templars running Abstergo Industries who had kidnapped Desmond Miles and put him in the Animus to view that very genetic memory.
Altair's Codex
Altaïr Ibn-La'Ahad's Codex included a map created by him marking down different locations. After being lost at sea, it was recovered by Ezio Auditore da Firenze who had to use his Eagle Vision to decipher it.
Precursor Boxes
Precursor boxes, also known as Isu Data Caches, occasionally projected maps when powered up. One was used by the Haitian and American Brotherhood of Assassins to locate the Seismic Temples in Haiti, Portugal, and the Arctic Ocean.