Castle-On-High

Castle-On-High is one of the five Core Worlds and the the seat of the noble House Einbull. It is an ocean world located in the Galilei Arm. It has no moons. Castle-On-High's geography is unique as the majority of its populated landmasses float up to three miles above sea level. Castle-On-High is ruled from Cazaral - the city in the sky. The capital city is a large metropolis built out of the ruins of pre-Calamity civilization. The bulk of the city takes up a large skyland, and is networked with several smaller skylands to make it possible to traverse from one to the other easily via cruiser or skylift. At the center of the city is Einbull Keep, a castle that has stood since ancient times.

Prismatic Annulus

The Prismatic Annulus are the gleaming rings that encircle the planet Castle-On-High. Made up of a dense accumulation of ice, rock, and fluxium, they are highly refractive and appear like a rainbow in the sky to those on the planet's surface. The rings consist of countless small particles, ranging in size from micrometers to meters across that orbit around the planet. It is also the location of Citadel Durador, the unfathomably large space station that forms an artificial ring around the planet, built within the Annulus.

Geography

The crust of Castle-on-High is abundant in fluxium. The high density of the ore and its superconductive properties cause large land masses to float high above the planet's surface. These land masses are stable enough to support settlements, even large cities, without any seismic disturbance. This has resulted in two distinct planes: the Upper Strata, wherein the nobility and privileged class dwell (many on their own private Skylands), and the Lower Strata, where the working class toil.

Natural Resources

With the advent of the flux drive, Castle-on-High built a thriving industry around mining, refining, and exporting the resource it had a near monopoly on. This is despite the dire risks involved in the mining on the planet's Upper Strata. There have been numerous instances where fluxium mining has resulted in the collapse of segments of Upper Strata and of entire Skylands.