Swamp of Secrets

The Swamp of Secrets was a swamp at the floor of Karda Nui. It's features included loads of mist. It was formed 1,000 years ago when Voya Nui split off from the Southern Continent and the sea water flowed in as a waterfall, but it was eventually exhausted by the actions of Matoro. How the Mistika could see through the mist may be revealed. It was home to a host of different Rahi. It was also home to the Mistika Makuta: Gorast, Krika and Bitil. The Toa Mistika Nuva now know that the Mask of Life is now a Toa, fighting alongside the Phantoka, and have discovered something of equal importance: the Codrex.

Toa Nuva
When the Toa first got here they split up into two groups, with Tahu, Gali, and Onua going into the Swamp of Secrets.