According to the book, there should only be one magic crystal in the Teleport Labyrinth.
However, there's the possibility that it wasn't originally a teleport labyrinth but just a normal labyrinth you can find anywhere else. Then it collided with some kind of ruins, and became the teleport labyrinth, as well.
Some kind of ruins.
Right, for example, teleport ruins.
"What is that, a book you say?"
And there Roxy voiced a question.