Iron maiden

An iron maiden was a medieval Earth torture device that consisted of an iron frame in the form of a maiden – hence the name – that was enclosed around the victim who would locked inside and tortured.

After being locked-up in chains in an illusory castle on Pyris VII in 2267, Captain Kirk analyzed the various manifestations – dungeons, curses, skeletons, and iron maidens – observing that they were all Earth manifestations, leading Doctor McCoy to theorize that they were experiencing an Earth parallel development.