N/A (black hole)
1x Earth gravity
~800 billion Drakonians
One huge city
Drakonia is an artificial planet (or a Dyson sphere not around a sun) created around a black hole millions of years ago. It was heavily modified and expanded upon by the Drakonians when they discovered it, whose homeworld had been destroyed by a supernova. It is now the capital of the Drakonian Empire. Due to the planet's artificial construction, massive shield generators and engines are integrated into the structure and powered by the black hole. It is rumored that it is capable of instantly "Teleporting" across space. Drakonia is best described by imagining 1920's New York City (Huge Art Deco skyscrapers, elevated trains, etc), but with lots of "steapunk" industrial buildings (Factories, power stations, etc) and state-of-the art railguns. It is always cloudy thanks to the artificial atmosphere, and often rainy. There is no sun, so the streets are artificially lit.
The Arc is a massive superstucture in the shape of a ring, situated in orbit around Drakonia's equator. It has a thickness of around 1.5 kilometers and is supported my massive elevator/pillars located every 10 degrees (or ~.17 radians! the more you know!). Besides a massive amount of orbital defenses, factories, and habitation centres, the Arc, boosted by Drakonia's own power, serves as a huge particle accelerator, thus providing almost all of its own power needs. An interesting feature is the massive structure that moves on rails on the bottom of the arc, orbiting Drakonia every 25 hours. It provides artificial light of about half that of an average star, both for health reasons and to vent excess particle radiation in a harmless manner. Additional lighting is installed in the form of large "strips", with one on each side of the Arc. Completed in sub-sections over the past 60 years, it was finally assembled during the early years of the Drakonian Civil War.