What is the thorn bush pit, and how is it important to the story?

The Thorn Bush Pit lies in the Northern Kingdom. It was made from clippings from the thorns surrounding Sleeping Beauty's castle, as she slept by the witch who told the journal writer about the Wishing Spell. The witch was trapped by the thorn bush and no one came to help her. Before she died, the witch cast a curse so that the thorn bush would trap anyone who gets close to it. Since then, anyone who wants to get rid of something comes there.