Beyond Neptune lies the Kuiper Belt — a torus of icy bodies from the Solar System's formation — and the scattered disc, where gravitational encounters with Neptune flung objects onto eccentric, inclined orbits. This scenario includes the largest trans-Neptunian objects: Pluto, Eris, Haumea, Makemake, Sedna, and other classical belt and scattered-disc denizens, with Neptune marking the outer edge of the giant-planet zone. Sedna's 11,400-year orbit never brings it within 76 AU of the Sun, hinting at an undiscovered distant perturber. The Kuiper Belt is the source region for short-period comets and a fossil record of the outer Solar System's early dynamical history.