User blog comment:Cybberd1/New World Map Location Translations/@comment-180.191.115.31-20151006092535/@comment-211.100.3.156-20151006093913

“Towards the east there is a city called the Sea City, towards the south there is another city created by the one name Eight Desire King, it’s the city you must be most wary of. Eight Desire King’s City … is a floating city in the desert.”

“Floating city?”

“This is merely hearsay, and may not be accurate, but there is a metropolis below the floating city. As if the floating city can generate an unlimited amount of water, the metropolis is entirely surrounded by magic enchantment, such that people cannot imagine it is in a desert.” Read it more in LN Vol 4 early chapter where Ainz brought back a map and tell albedo about it.