From Tapestries MUCK
The Cloud Castle is a fixture that predates almost everything else on the world. It's origins are unclear and the subject of much debate. It literally floats in a magical cloud nearly a mile off the ground in the general vicinity of Layleaux, which lies just south of the only connecting point to the ground.
Much of the castle is magically sealed away, and never has been explored. There is also an unused hottub that is actually in the cloud itself, and a bar that has long since gone out of use.
Hall of Tapestries
The most notable portion of the castle is the Hall of Tapestries. This hall once contained many active Tapstries that connected to other worlds, but now only the one that connects to the arch north of Layleaux is active. The rest have grown dim and powerless.