Looks like an old mine or something, but at about 25 seconds in, you focus on a triangular rock. It has what would be an "X" on it towards the right side . The long leg of the "x" points at the median on the right leg of the triangle. Here's what I would check. Use the triangular rock as the top corner of a triangle. Find the 2 other corners, they can be anything, boulders, trees, a rock outcrop with a triangular cut, but something indicating "triangle". Find the lower right corner and go to the spot that is midway between the top rock and the lower right corner and see what is there. That's where I would carefully dig first, and mark compass directions on any strange rock (especially one that points) dug up in that particular spot.