Epic Cataclysm (Aion)  

Aion Wikibase™ Lore

Nearly a thousand years ago, in Atreia, the world of Aion, an act of betrayal in the midst of a peace conference led to the destruction of The Tower of Eternity, the source of life, light and Aether. This destruction caused the Epic Cataclysm, sundering the hollow world in half. The upper half got the short end of the remains of the Tower, which gives no light or heat, plunging the land of Asmodae into darkness.

The lower half, Elysea, has a mostly intact half of the Tower, and it's magnificence blazes around the clock, bathing all the Elyos in it's glory.