Sundial

The Sundial was a large, organic structure that served as both an entrance to the Mangaia and a means of locating the Codrex.

History
Around the time the Toa Mata were searching for their Kanohi, Onu-Matoran miners discovered a large sundial buried in a seemingly impenetrable rock layer in an Onu-Wahi mine. While exploring, Takua joined the prospectors examining the sundial. One of them asked him to deliver a message to an astrologer he knew. The astrologer determined that when the shadow from the sundial's gnomon hit the four o'clock position, something would happen. She then gave Takua a gnomon she had found some time ago, which she suspected went with the sundial. Sure enough, the gnomon fit, and when Takua shined a lightstone on it so that it indicated four o'clock, the sundial opened, revealing a passage through the rock layer with a gold Kanohi Hau at the bottom. Later, after Takua's party of Matoran had successfully defended the Kini-Nui from hordes of Rahi (with the help of the Onu-Koro Ussalry, the Ta-Koro Guard and the Le-Koro Gukko Force), Takua was asked by Onepu to travel to Onu-Koro and inspect the sundial, as the Kanohi he had seen before had now disappeared, and a new passageway had opened beneath it. None of the Onu-Matoran miners would travel through the passageway, as they believed it was another entrance to the Makuta's lair. The miners turned out to be right, as Takua then used it to make his way into Makuta's lair and witness the Toa Mata defeat the Master of Shadows.

Much later, after the Matoran had returned to Metru Nui and the Toa Nuva were following a list of tasks needed to restore the universe to working order, a strange voice told Lewa to return to Mata Nui and retrieve the sundial, which he did. The sundial was then inexplicably shrunk, and given to Takanuva by Toa Krakua. Its purpose was to locate the legendary Codrex. Whenever Takanuva shone light on it, the shadow pointed to the Codrex.

The sundial had eighteen sections on it, representing Spherus Magna's thirty-six hour day.