The Cave of Tiandra was the cave complex where Tiandra hid the Azlanti relics she got in the later years of the Age of Darkness. Generations later, Arustun discovered and miraculously interpreted these relics enabling the sunrise of the first human civilization after Earthfall: the Jistka Imperium.
Most Jistkan scholars agree that the legendary Cave of Tiandra is located northeast of what is now Manaket on the Inner Sea coast of Rahadoum. The cave appears to be nothing more than a hillside grotto with a single barren chamber and its low ceiling eroded. However a narrow pitch in the back of the entrance cavern reveals that beneath the initial level lies a vast network of tunnels, dens and hollows, with soaring drops and huge domes. The presence of crysmals has led the scholars to believe that the Cave of Tiandra once had a link to the Plane of Earth and perhaps other planes. This may explain how Arustun gained the miraculous insight from the relics found there, in -4160 AR.