So here’s something. You can hop over a fence or a wall in Minecraft IF its a double wall (or fence) and you place a block on either side of the wall. And animals can’t follow you. Or mobs. (Well, rabbits can make it. And spiders.) This is called a stile.
Definition of “stile”: it’s a step or set of steps that allow you, but not farm animals, to get over fences or walls. You’ll find them in Europe where public walking paths go through farms. I hopped over many when I used to live in England, where right-of-way paths through farms is a thing. Something to do with civilization before cars.
I’ve just started investigating this feature — or is it a bug? — so I don’t know all the ins or outs. If a fence is the upper half of the structure and a wall the lower, you can use slabs and stairs on both sides of the stile. If the upper half is a wall, it seems you need at least one full cube block one side, and on the other you can have a block, slab or stair. If you have double fences, you can’t use slabs or stairs.
See, I made a video about it! It’s on Youtube. And it’s my first video. Say hi if you get there!