IRON MAIDEN _ Tavern Puzzles Heavy Metal Disentanglement-Style Brain Teaser _ BONUS Twisted Nails Puzzle Old fashioned heavy metal brain teaser disentanglement puzzles. Bonus: Twisted Nails Separate the Nails Puzzle. Objective of IRON MAIDEN is to remove the large RING. (indicated by BLUE arrow) Replacing the RING to the starting position is equally as challenging. Rated as a level 2 "Intermediate" (on a scale of 1 to 4). Packaged in sturdy white box, cloth bag and with solution.