Fall Through a Wall

From Glitches

From the game Ninja Gaiden for the NES.

In the level where you're on the side of a mountain, there's a part where you have to use a Z-shaped jumping pattern to get to a low ledge. This is difficult because you're likely to fall off the screen. But if you climb up the wall that's above the low ledge instead, you'll fall through it at the top and easily land on the low ledge without risking anything.

Taken with permission from Flying Omelette.