|Primary Residents||None, no longer existent|
|Former Residents||Ga-Matoran, various Rahi|
|Location||Somewhere to the east on Mata Nui|
Most of what was considered Ga-Wahi was underwater, but there were also grasslands and white-sand beaches on the western half of it, ultimately touching the Mangai and Mount Ihu. The northern side was lined with high sandstone cliffs, from which Naho falls constantly flowed. Floating on the sea was the village of Ga-Koro, which was constructed from bamboo and extremely durable plants resembling lily pads and seaweed. A bridge connected the village to the beach. The seas below Ga-Koro were abundant with all sorts of life, being home to (among other creatures) Takea sharks, schools of Ruki fish, Keras crabs and even the fierce Tarakava lizards.
Minutes after the Great Cataclysm, Ga-Wahi formed as a part of Mata Nui. Several days later, the Toa Metru arrived in search of a new home for the Matoran of Metru Nui. Nokama decided Ga-Wahi would be a suitable place for the Ga-Matoran - the large amount of water made it reminiscent of Ga-Metru.
Later, the Visorak on Metru Nui drove several Rahi from that city to the island of Mata Nui, including several to Ga-Wahi. Eventually the Toa Metru returned with the amnesiac Matoran of Metru Nui, became Turaga, and started a new life on Mata Nui.
Nokama and her Ga-Matoran found a lake that they named after the late Toa Mangai Naho. There, they built a village of durable lily pads that they called Ga-Koro, meaning "Water Village". They named the location itself Ga-Wahi, meaning "Water Region".
In 1 AGC, Teridax came to the island of Mata Nui and began infecting Rahi and using them to keep the Matoran from returning to Metru Nui. This went on for hundreds of years. In 1000 AGC, Gali and the other Toa Mata arrived on the island. Gali became Ga-Wahi's protector after arriving on Mata Nui.
After the Toa Mata defeated Makuta, he unleashed the Bohrok onto the island. The Bohrok had originally been purposed to clear the camouflaging flora when the Great Spirit destroyed the island upon leaving the planet he was currently observing from. However, they had now been awakened when they were not intended to and began to destroy Ga-Wahi and the other regions of the island even while there were still living beings in it. Eventually, the Toa Mata sent the Bohrok swarms back to sleep, right as a swarm of Pahrak were about to decimate Ga-Koro. After the Bohrok Wars, a deep vault was dug on the shores of Ga-Wahi to seal in the Krana captured from the deactivated Pahrak, never to be opened again.
After the coming of the seventh Toa and the rediscovery of Metru Nui, Ga-Wahi was abandoned as the Matoran left for Metru Nui. When the Toa Nuva later freed the Bohrok swarms so they could do their job at the right time, Ga-Wahi was laid bare. A few days later, when the Great Spirit Mata Nui was finally awakened and stood up, Ga-Wahi fell off of his face and into the Endless Ocean, destroying it.
Ga-Wahi was the smallest region of Mata Nui because the majority of it was underwater. Notable features include:
- Lake Naho/Naho Bay (one of Metru Nui's sunholes was underneath it)
Ga-Wahi was mostly inhabited by Ga-Matoran. It was also inhabited by several species of Rahi, mostly aquatic. These include Dermis Turtles, Hoi, Tarakava, Takea, Ruki, Keras, Lightfish, Razorfish, Razor Whales, Cave Fish, Gadunka, Makuta Fish, Proto Drakes, Waikiru, and at least one Great Temple Squid.