Planet of Lana

You will find this during Chapter 5. Near the start of the level you will come to a section with a weight puzzle. To the right of the puzzle is a moss covered wall and a rope. Climb the rope and swing/jump all the way to the right to find a hidden ledge. Inside the cave you just need to interact with the stone using to unlock the achievement.

Visual Guide:

Just to contest guide #1 here saying "Near the start of the level," this is nowhere near the start of the level, but moreso near one of the first puzzles in the level. After the start of the level you have to walk for a good five minutes or more, then scream for your friend, like the maniac your character is, at the edge of a cliff, which takes another good forty seconds. But eventually you will come to the first puzzle involving a black box that you have to manipulate in order to jump to the next cliff. The next puzzle after this is the weight puzzle mentioned in guide #1. There is, indeed, a rope toward the right that you can swing on back and forth maybe 5-6 times that gives you enough momentum to jump to the hidden cliff on the right. I swung like two times in each direction (left/right) before jumping and successfully making it to the hidden cliff. Good luck, everyone! Get those shrines.