This page explains how to find the Ketoh Wawai shrine.
How to Reach the Shrine
From Rin Oyaa Shrine, go northeast along the road, then when the road goes past a valley between the mountains, go east through that valley. Continue going east through this area. Eventually, you might see a Lynel up ahead. If you don't want to fight it, climb up to higher ground but continue going east.
After a while, you will see some stone statues on a slope. Go up that slope toward the tree. Cross the bridge beyond the tree and you will be in an area of permanent darkness.
Pick up the nearby torch and light it with the bird statue torch. Light the nearby bird statue. All of the bird statues in this area are looking in the direction of the next bird statue, so go in that direction to find the next bird torch, lighting each one as you go. Be careful not to run or your torch will go out. If you encounter enemies, try to stay near a bird statue so you can go back and light your torch with it after you are done fighting.
If you are near a bog and don't want to fall in, you can use Cryonis to see the edge of the bog.
After following the bird statues, if you find two statues that face each other, look for another bird statue between them. This should lead you to the Hinox at the end of the maze. Before fighting the Hinox, light the two bird statues past the shrine platform. There are two more bird statues beyond this, but when you light them, you might end up waking the Hinox.
Shoot the Hinox in the eye if possible, then hit it with your strongest weapon until it gets back up. Try to use a torch or flame weapon on the wooden armor on its legs so you can do more damage.
When the Hinox dies, it drops an orb. The orb is always glowing, so you can use it to explore this area more if you wish. Otherwise, put the orb into the shrine pedestal to make the shrine appear. Go into it and open the chest to get an Ancient Core. Then talk to Ketoh Wawai to get the Spirit Orb.