Heran
It took their group a little more than 3 hours to reach the walking city.
It was situated on the back of a behemoth beast called 'Heran'. It looked like a close relative of the long-necked sauropods back from earth, only much bigger. It was several tens of kilometer long with a neck that reached all the way into the lower atmosphere, with its head occasionally above a layer of clouds. (Img in authors note)
These were part of a rare type of beasts that were owned by powerful families and institutions for many different occasions ranging from War or to simple transport missions for important people or materials over a long distance.
Each beast had its own special ability but they had a few things in common.
For one, they never rested. They didn't need to. They never slept or haad to lay down. They were like machines that could go centuries on one trip if need be.