Existe, mas não sabemos nada sobre isso.

A parede na Plataforma 9 3/4 pode ser passada:

"Not to worry," she said. "All you have to do is walk straight at the barrier between platforms nine and ten. Don't stop and don't be scared you'll crash into it, that's very important. Best do it at a bit of a run if you're nervous. Go on, go now before Ron."
_{Harry Potter and the Sorcerer's Stone, chapter 6}

Você poderia dizer que a barreira realmente não existe, e isso é uma ilusão, mas acho que o que aconteceu no segundo livro refuta isso:

Both of them bent low over the handles of their trolleys and walked purposefully toward the barrier, gathering speed. A few feet away from it, they broke into a run and -
CRASH.
Both trolleys hit the barrier and bounced backward;
_{Harry Potter and the Chamber of Secrets, chapter 5}

No entanto, não sabemos nada sobre o feitiço além do que ele existe.