Zebes was the site of the events of Metroid (and its subsequent remake, Metroid: Zero Mission) and Super Metroid. Zebes was the adoptive home of a young Samus Aran, who was raised by the Chozo after her parents were killed in a Space Pirate raid. The Chozo population on Zebes was decimated by their own defenses when their supercomputer Mother Brain went insane and turned against them, allying herself with the Space Pirates. Samus returns to this planet as an adult, charged with destroying the Space Pirates who have set up a base in the subterranean catacombs of Zebes, coming face to face with her parents' murderer Ridley, as well as facing Mother Brain herself.
Zebes' surface is unremarkable, and was largely ignored by the Galactic Federation as it was uninhabitable by humans. They named the surface of Zebes 'Crateria'. Researchers could only explore so far underneath the planets crust and into the caverns left behind by the Chozo, blocked by lava and acid pools. They were amazed to find an ecosystem of flourishing plant and animal life under the surface of Zebes, and named the lush jungle area Brinstar. Other locations named but unable to be explored were Miridia, the sunken caverns of Zebes, Norfair, the volcanic lava-filled area, Chozodia, site of an ancient Chozo temple, as well as an ancient wrecked ship that had crashed onto Zebes in ages past. Zebes was also the site of the Space Pirate base, Tourian. In Metroid and Metroid: Zero Mission, Tourian was built closer to the surface of Zebes. After its destruction in Metroid and subsequent rebuilding in Super Metroid, it was build much deeper under Zebes' surface. Because of this, when Tourian was destroyed by Samus in Super Metroid, the proximity of Tourian to the planets core resulted in a chain reaction that destroyed the entire planet.
The inhabitants of Zebes were as varied as its respective areas. As well as its diverse fauna and flora, Zebes was originally home to Chozo, who were wiped out by Mother Brain when she went rogue. Also, the Space Pirates set up a base there to study and reproduce Metroids that were brought there by the Chozo in ages past. The manual of Super Metroid labels the Space Pirates as Zebesians, but since the Metroid Prime series this has been debunked, as the Space Pirates are a race that originated from the previously undiscovered Space Pirate Homeworld, and not Zebes as first thought.
The planet Zebes is split into these seven regions: