Take the Sunrest Bridge portal into Stonefield and climb up the hill behind the portal, heading to the puzzle at /setwaypoint 4577 4975
The Puzzle
The puzzle is 5 telescopes in a semi-circle around a lever
All you need to do to complete the puzzle is click the telescopes in the right order and then click the lever when all the lights are on. You need to do this pretty quickly, angle yourself ready to run to the next telescope so you can go as soon as the light turns on
Once all the lights are on the reward chest will appear in the middle of the puzzle.