Opia

The planet Opia is the primary setting of Opia. That should really go without saying, but hey!

Opia is slightly smaller than the planet Neptune in our own universe, yet is a terrestrial world, like earth. Most of it is covered by a vast ocean which is littered with various landmasses, ranging from massive continents to tiny islands. These are detailed on the Locations page.

Above the cloud layer on Opia, there is a layer of corrosive gas which prevents any kind of prolonged contact, even for synthetic materials. This prevents the use of aeroplanes for long distances, and explains the prominence of personal gyrocopters. The only effective way to travel such long distances quickly is via an orbital slingshot, which is a dangerous technology.