|Location||In between Onu-Wahi and Ko-Wahi|
The Onu-Koro Highway was constructed during the Dark Time as a safe means of transport between the two villages. However, due to the darkness and isolation of the tunnels, they eventually fell out of disuse.
They were used by Takua and Jaller during their search for the Seventh Toa. It was when the two companions were travelling through these tunnels that Takua encountered Makuta Teridax who spoke to Takua through the shadows and convinced him to abandon his and Jaller's quest for the Seventh Toa.