Mategriffon

Mategriffon or Matagrifone or Mathegriffon or Rocca Guelfonia was a medieval castle in Messina, Sicily, located in what is today Viale Principe Umberto. Its strategic position upon a rocky hill close to the historic city centre gave a commanding view of the harbour and Strait of Messina. In the 19th century it was converted into a prison. Prior to its destruction in the 1908 earthquake it comprised a square dungeon with ramparts and reinforced by polygonal towers. Only an octagonal tower remains standing and is incorporated into the 20th century Shrine of Christ the King church, a visible Messina landmark which dominates its skyline. The name Matagrifone signifies "Greek killers" or "kill-Greeks" due to the population of Messina having been predominantly of Greek ancestry.

Prison data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).