Cones

Ropes, cones, and plant pots have magical powers in Japan. It's true. Whereas in England these things are a mere inconvenience to step over or around, and completely ignore, in Japan this is how you stop people from entering places they shouldn't.

The owner of the land in the photo must really want to keep people out because he's used all three of the magic items, but usually a single piece of rope is enough to keep absolutely every single Japanese person out. Amazing.