The iron cages of St Lamberti

Excerpt from wikipedia:

The army of Münster was defeated in 1535 by the prince bishop Franz von Waldeck, and John of Leiden was captured. He was first taken to a dungeon in Dülmen, then brought back to Münster. On January 22, 1536, along with Bernhard Krechting and Bernhard Knipperdolling, he was tortured and then executed. Each attached to a pole by an iron spiked collar, their bodies were ripped with red-hot tongs for the space of an hour, then each was killed with a dagger thrust through the heart. Their bodies were raised in three cages above St. Lambert's Church, the remains left to rot. Their bones were removed about 50 years later, but the cages have remained into the 21st century.