You'll be standing on Symmetry Island.
Map
Desert Obelisk
SW #1
>
>
Where you stand to solve it is a little distance from where the puzzle is located.
Notice that symbols 1 and 2 are very similar on this obelisk face.
The black oven thing at the Glass Factory is the starting point for a short path you can trace. You'll need to find the right angle.
Additionally, notice that symbols 1 and 2 are very similar on this obelisk face. You'll probably find the two of them at about the same time, if you think symmetrically.
Complete spoiler:
Roll over each black area below for hints.
Each new hint gives away more than the previous one.
Head toward the top of Symmetry Island.
Look across at the Glass Factory.
You have to have solved at least some of the Glass Factory puzzles.
Prerequisite for solving:
Hints about the location:
You need to have opened the gate to Symmetry Island.
Show hints
Intro
This one is okay. It doesn't require any special puzzle solving -- just standing in the right place and looking.
THE WITNESS - ENVIRONMENTAL PUZZLE HINT GUIDE