It is an ancient map/blueprint hidden by the Remnants ancestors that leads the way to the hidden ruins of Kitezh, and the Divine Source. The map is shown by having light go through the 'crystal' show in the image, then the light makes its way through the cracks.
Lara sought the Atlas from the Cathedral where it had been hidden in order to find Kitezh, The cathedral itself was protected by a legion of the Deathless Ones, who killed any who tried to take it, though Lara was able to escape with it.
After viewing it, and discovering the location of Kitezh, the Atlas was stolen by Trinity's forces, who brought it to their field commanders, Ana and Konstantin. They used the large dome in a Soviet era weather station to find the location of Kitezh. No longer needing it, they left it unattended, in the dome, where Lara later retrieved it.
Lara was gifted the Atlas by Sofia after she completed her Journey.
- The Atlas is no secret to the Remnants, a man revealed its existence, but not its location, when Jacob was threatened.
- The Deathless Prophet's people were highly advanced for their time and the invention/inventor of the Atlas would have been a legendary marvel amongst the ancient Empire. Lara states this advanced skill a few times during the final chapters of the game.
- To view the Atlas is a simple mechanism, controlled by two chains to lift the Atlas to the light, and to rotate the map. But the dodecahedron design of the Atlas is far more advanced, the work of mathematicians, metal workers and skilled architects.
- Lara first learns of the Atlas by a golden mural that circles a large statue of the Prophet, it states that his people forged the Atlas so that 'the Deathless Prophet shall always know his city and its secrets.
- Some have compared it to the Headpiece of the Staff of Ra, from Raiders of the Lost Ark.