Thou Shalt Not Pass

There is a very special Stone Labyrinth that is considered to be the most cruel and feared punishment in the country. It is a section of the imperial grounds that collapsed onto itself and fell into a deep pit underground, because it was originally constructed on a porous rock.
Many speculate that the place collapsed due to the high corruption of the previous dynasty. There were some plans to have the entire place filled up with dirt, so it is safe again and can be repurposed, but after the Crane Rebellion, followers of the clique were thrown in there as a punishment - to symbolise that they are no longer considered to be a part of the citizens and do not deserve to walk the earth.
After that incident it is still used as a way of punishing the worst crimes commited, although it is still used sparingly as most prisoners who were supposed to end up there chose to be executed instead. Despite the option that whoever manages to get out of there alive, would be absolved of all their crimes.
No one wants to end up among those tall, dark, sharp stone pillars.