The Cosmic Disk is a very small artificial ring galaxy constructed by the long left ancient hyper-advanced race, known as the Shapers. It houses vast amount of technology artifacts, facilities, structures, blueprints and other valuables left behind either by the Shapers or other races inhabiting it. Aside of natural formations, it’s also housing a complex set of nearly unbreakable safety measures that makes way in and way out largely impossible.
Despite said safety measures, a handful of space-faring races could enter and spread; at the time of the main story, four major and thousands of minor sentient races are inhabiting it, in a very diverse and eventful thread of history involving wars, technological breakthroughs, gold rushes, and the rise and fall of countless civilizations.
The Cosmic Disk is the location of every story regarding Terminus Nation.
As the name implies, the Cosmic Disk has an unusual shape and structure: being a special type of ring galaxy, it has very small amount of stars scattered in its body - the majority of the cosmic matter is concentrated around its gravitational center and around the edge.
The Cosmic Disk is, in fact, not a natural galaxy but was artificially created by Shaper activity. Galaxies of this scale never form naturally, yet even for such a race, a task of this scope must have taken incredible amount of time and effort. As a result, the Cosmic Disk is a very small portion of intergalactic space (though some assume the Cosmic Disk is actually lying inside another, proper sized galaxy - there is no way to prove or dispute this)
Because of the supernatural nature of the Frontier and the distorting force field of the Beacon World (see below), and also considering the nearly impossible tech level of interstellar space travel and heavy restrictions in interplanetary space exploration, there are only rough estimates about its size. Said estimations take between 400 and 10 000 light years, but these data, like the distance of other stars and galaxies can not be calculated for sure results.
The number of celestial bodies inside the galaxy are also unknown, but according to astronomers, it definitely consists of less than a million stars.
Beacon World: A Shaper construction within the middle of the galaxy, with the size of a supermassive black hole. Being an enormous hollow orb-shaped object, the interior can be approached through a Shaper Obelisk somewhere in the galaxy, but no one knows, where it is. This construction describes the entire web of Planet Monuments and randomly sends portions of this data through the universe. It should be noted that it emits an extremely strong red light pillar, making it visible in the entire galaxy.
The Frontier: The edge of the Cosmic Disk; a chain of unidentified astrological objects, forming a mysterious space cloud. Planets in this region have harsh environment, while stars have extremely strong gravitational fields, making space travel even harder. For the Republic, it is considered the final edge of the area of interest.