>>712880574
Fake walls. Any of them. All of them

Scenario 1: You by chance move through a wall and discover that fake walls exist, and now have to try every single fucking wall just in case
Scenario 2: The above, but the devs only did it for this one secret. There are no other fake walls. You still try and hit/move through every single wall in the game not knowing this.

Special mention, items behind trees or bushes/buildings you can't see in fixed camera angles.