Crusader castle in Bodrum harbor, Turkey/ views are stunning. Bodrum Kalesi was built by the Knights Hospitaller starting in 1402 as the Castle of St. Peter or Petronium. The construction of the castle began in 1402 under the German knight-architect Heinrich Schlegelholt. Construction workers were guaranteed a reservation in Heaven by a papal decree of 1409. They used squared green volcanic stone, marble columns and reliefs from the nearby Mausoleum of Maussollos to fortify the castle.