The Witness 100% Walkthrough (Part 11) - Mountain shaft puzzles and secrets

This is the eleventh part of my guide to complete The Witness with 100% of the puzzles with a natural progression feel. No major spoils here, this means no puzzle is solved if the knowledge for it hasn't been uncovered. All secrets are explained and shown, as well as what the puzzle rules are and why puzzles are solved a certain way and not another. This walkthrough tells you the rules, allowing you to pause and then do the puzzles on your own. This makes the progression natural. A perfect guide for those unwilling to search in a lost fashion, but who don't want to jump ahead of the natural progression of the game. ATTENTION: at 8:40 till 12:40 things may get mildly epileptic!!