The Chozo Ruins are a region on Tallon IV, and the site of a lost Chozo colony. The city's founders had achieved spiritual enlightenment and had shed their corporeal forms in doing so, but the arrival of Phazon upon Tallon IV had thrown the Chozo spirits into turmoil.
In some time long ago, Chozo colonists built a city upon Tallon IV, seeking to reach enlightenment by living in perfect harmony with the planet's natives and abandoning the technologies they had once depended on. In time, they had reached their goal and ascended to a higher plane of existence. However, their peace was not to last. A Phazon Leviathan crashed onto Tallon, the sheer force of the impact forcing the Chozo to return to the planet. The Phazon began to have a severe impact on Tallon's biosphere, prompting the Chozo to build a temple at the source of what they called "The Great Poison" in order to contain it. However, they were too late to stop it from affecting themselves, and soon all of the Chozo were transformed into vicious ghosts by the corruption. Currently, the ruins are abandoned and generally avoided due to the threat of the roving bands of Chozo Ghosts.
The Chozo Ruins is built from carved rock with simple structures made from wood, stone, metal and rope bindings, and water was carried throughout the city by canals and piping from a fountain atop a spring. Although written lore states the Chozo inhabitants abandoned advanced technologies, various mechanisms, including power generators, a Hive Mecha and Incinerator Drone are found across the ruins. The waters that coursed throughout the ruins were poisoned by a large mutant plant called Flaahgrah, which had caused most of the Cyrlic Trees and other plants throughout the ruins to die.
There were also some areas that contained recorded Chozo lore etched into the walls. Some of which were written around the time of their arrival to the coming of Phazon, but others appear to have been recorded during Samus Aran's mission on Tallon IV.
Certain sites throughout the ruins are also haunted by Chozo Ghosts, spiritual Chozo entities driven insane due to Phazon Corruption.