Location from remembrance-of-earths-past by
The eight-planet star system around the Sun — the stage for the Doomsday Battle between Jupiter and Saturn, the Bunker Era retreat behind the gas giants, and the dual-vector foil's final two-dimensional collapse of everything inside the Kuiper Belt.
The Solar System is humanity's only known refuge for most of the trilogy and, by the end, the murder weapon used against it. The Doomsday Battle is fought between Jupiter and Saturn. The Bunker World cities are constructed in the gas giants' shadow zones. Singer's dual-vector foil enters from the outer system and flattens everything inside thirty AU like a wet brush across a watercolor.
A flat disk centered on a small yellow G-type star, eight planets in nearly coplanar orbits, asteroid belt between Mars and Jupiter, a sparse Kuiper population beyond Neptune. By the Bunker Era the gas giants Jupiter and Saturn host city-cylinders strung along their L-points, hidden in their shadows from any Dark Forest weapon coming from the inner system.