Standing on a ship, Zordlan started casting the spells that would take the ship up, to the floating island of [placeholder].
Long ago, multiple powerful spellcasters joined forces and cast a spell, so powerful that it would change the world as everyone knew it. Islands started forming, not the type you'd find in an ocean, but ones hovering in the air, almost like inverted mountains.
And now, thousands of years later, the floating islands are common. If you look up, you'll see at least two, usually more. Most of the time, they're small. But sometimes, you can spot a really big one.