Quarry Achievement in The Witness
Activate the Quarry laser.
How to unlock Quarry
The Quarry area is located in the back of the map between the Desert Ruins and the Shady Trees area. The Quarry puzzles use black and white squares, multicolored squares, suns, and tetris shapes, so it is highly recommended to make this one of your last areas.
Thankfully the Quarry puzzles themselves aren't too difficult. Use THIS LINK for the puzzle solutions in the Quarry.
Upon activating the panel on the laser, the achievement will unlock.