The Kuiper Belt — A belt made up of icy bodies
Beyond the orbit of Neptune, you get the Kuiper Belt. It is one of the largest known structures in the Solar System, being 20 times wider than the Asteroid Belt. The huge belt consists of known dwarf planets and millions or maybe even trillions of icy bodies. Dwarf planets such as Pluto, Eris, Makemake, Haumea etc. lie in the Kuiper belt. The Kuiper Belt is generally the origin of short-period comets (i.e, comets whose orbital period is equal to or less than 200 years). Objects that lie in the Kuiper belt are known as Kuiper Belt Objects or trans-Neptunian Objects.
The Kuiper Belt is being explored by the New Horizons spacecraft which has already visited Pluto and another body named Arrokoth.