The ancient Atlantis - or "Ocean Spire"- is, even today, the ideal many mages hope to achieve. It was here that mortals first learned how to wield the powers of the Realms Supernal and magic was set down in a codified system.
The exact nature of Atlantis, however, is difficult to pin down. Imperial Magic and Ascension are able to alter the Tapestry in fundamental ways, erasing timelines and twisting destinies, which likely happened when the Exarchs enthroned themselves. In the broken remnant of the Fallen World, Atlantis is more symbol than reality. Modern scholars have 36 locations that are debated to have been the site of Atlantis (not counting ideas about locating it in one of the Realms Invisible), but since everything in the Fallen World is - to an extent - veiled by the Lie, difficulties and inconsistencies are abound.
In the Times Before, humanity lived under the constant threat of spirits and monsters. At this time, some humans dreamt strange dreams of an isle crowned by a single mountain- a mountain encircled by dragons- and free of the depredations of spirits. In time some who heard the island's call left to seek it. Upon finally reaching it they were shown new visions: in their dreams they saw techniques to give them power and the ability to drive back the darkness swamping humanity. Entering the caves of the island's spire, the travellers went into deep meditation and were tested by their other selves, their daimons. Some failed and left the spire disheartened; those who succeeded, returning triumphantly bearing the fire of the Realms Supernal, were the first mages.
As the power of the first mages grew, so did Atlantis. High Speech united men and women from all parts of the world, for only those who let their dreams guide them could find the city. Ruled by mighty priest-kings advised by the viziers of the Vox Draconis, administered by the Visus Draconis, and protected by the Ungula Draconis from threats such as the Timori and the beings later known as the Bound, the city prospered. During this time the Alae Draconis practiced the Ars Mysteriorum freely, unfettered by Disbelief or Paradox, and discovered incredible magical knowledge.
Occasionally, a human from another land would receive the gifts of magic, but these were rare, isolated cases. Many of these foreign sorcerors would destroy themselves with their own power, or be killed by the superstitious common folk. But the Ars Mysteriorum thrived on Atlantis, and only here were they set in writing for acolytes to study, that they might not be a danger to themselves with their powers.
As the mages' powers grew, so too did their pride. After many generations, the Awakened of Atlantis turned on one another in the First Wizard's War, one side seeking to gain physical entry to the Supernal Realms and become gods, the other wishing to preserve the natural order of things. Those who sought godhood won, driving the others from Atlantis.
The leaders of the usurpators then combined their powers, building at the heart of Atlantis a ladder to the Supernal Realms. Climbing this Celestial Ladder to other planes of existence, they assaulted the rulers of these realms, cast them down and claimed their powers for their own. With the Supernal Realms touching the Material universe, the masters of those realms became true gods, but the universe began to buckle under the weight. Chaos reigned in the world of mortals, and the very fabric of reality began to tear itself apart.
In a desperate alliance with the Timori, the exiled mages regrouped and assaulted Atlantis, seizing it and climbing the Ladder themselves. They began to storm the palaces of the celestial magi. In the battle that followed, both sides suffered terrible losses. Mages on both sides were flung from the Supernal Realms back into the world, and the conflict began again in the material realm.
During the height of the battle, the Celestial Ladder collapsed and where it had been, a yawning void gaped open that drove a wedge between the Realms Supernal and the Realms Material. Stronger than ever before, the Abyss was now nearly impenetrable for souls, designed to keep an aberration like the Celestial Ladder from ever being built again. The Gauntlet between the worlds of flesh and spirit rose as the tapestry itself restructured.
The foundations of Atlantis were destroyed in the conflict, and the island city fell apart, sinking into the waves of the thrashing sea, its burning wreckage being swallowed by the dark waters. The mages fled, scattered themselves across the world, returning to their old homes, and trying to regain the power they once had, in what is called the Exile.
Due to the watchtowers and the oracles, the mages of today have access to the knowledge of their forebears. Atlantean customs dominate the mindset of modern mages and many attempts have been made to rebuild the city, the most recent being that of the Phoenix Brethren. Four orders of the Pentacle claim Atlantean heritage and every attempt to change the society of mages is often faced with bitter resentment. Others hold that simply by emulating what they believe was part of Atlantis, the Diamond generated a powerful Supernal symbol that is True whether Atlantis existed or not.
Many legacies dedicate themselves to the heritage of Atlantis either by trying to restore it or by trying to reinterpret the idea of it. They point to Thule, Hyperborea, Shamballah, Atzlan, Lyonesse and similar myths to say that there has once been a Golden Age that the Hubris of men destroyed.
Across the globe, ruins of a pre-human civilization can be found that contain mysteries and legendary artifacts, protected by Temple Guardians and similar entities. Mysterium scholars argue fiercly over the authenticity of these ruins, if they are indeed Atlantean or part of the "Barbarian Kingdoms" that are sometimes mentioned in the myths.