This page explains how to find the Mo'a Keet shrine and solve the "Metal Makes a Path" puzzle.
How to Reach the Shrine
From Lanayru Tower or the nearby Soh Kofi Shrine, go north to a path that goes northeast. Follow this path, going left at the fork (the left side of the sign says Maw of Death Mountain). Soon after you go left, you will see a shrine in the distance. Keep following the path and you will reach Foothill Stable. Go east from the stable to reach this shrine.
How to Solve the Shrine
There are slopes where boulders are rolling down. Before going up the first slope, go past it and look at the ceiling. If you have bomb arrows, you can shoot the cracked stones in the ceiling to get a chest. It contains a ruby. If you don't have bomb arrows, or don't want to use them, there will be another way that you can break the cracked stones soon.
Go up the first slope, using Stasis to stop the oncoming boulder if necessary. Try to stop the boulder as soon as it comes down from above. Otherwise, it might block your path.
At the top of the first slope, go to the right, where you will find some magnetic boulders rolling down. Use Magnesis to stop the boulder, then go up the slope that it came down and you will find a chest. It contains a Knight's Broadsword. You can take the magnetic boulder back down to the lower level where you entered the shrine (using the magnetic boulder to block the non-magnetic one in the middle as you go down the ramp) and use the magnetic boulder to break the cracked stones in the ceiling to get the chest there.
Take the magnetic boulder to the ramp on the left where a lot of boulders are coming down. Use the magnetic boulder to block the other boulders so you can safely go up the ramp. You may need to press up to push the magnetic boulder forward through the other boulders.
At the top of the ramp, you can get the Spirit Orb from Mo'a Keet.