Note from an user Marie E.:
I knew someone who had attached a cat to a rope (I know it's terrible, sorry) and slowly dropped the cat in one of the "infinite" hole. The rope was pulled and the cat was removed from the rope. I can't remember if the rope had been cut or if the cat was simply removed (I think it was cut). The rumor has it that people live under the mountain and that the cat was freed by them.