Bodrum Museum of Underwater Archaeology

Located in southwest Turkey in the port city of Bodrum on a rocky area between two ports, Bodrum Castle was built from 1402 onwards by the Knights of St. John (Knights Hospitaller) as the Castle of St. Peter or Petronium. Confronted by the established Ottoman Sultanate, the Knights needed a mainland stronghold. Bodrum was chosen due to its proximity to Kos, where the Order had already built a castle. The promontory was previously the site of a Doric fortification and an 11th-century Seljuk castle.

The construction of the castle began in 1404 under the supervision of German knight architect Heinrich Schlegelholt. A transnational effort involving Italian, French, German, and English forces, the castle utilized squared green volcanic stone, marble columns, and reliefs from the nearby Mausoleum of Halicarnassus. The chapel was built around 1407, the three-storied English tower finished in 1413, and the first walls completed in 1437.

The castle features a square plan measuring 180 by 185 meters. Seven gates lead to the inner fortress, adorned with hundreds of painted coats of arms and carved reliefs including crosses, animal figures, and badges of grand masters. Fourteen cisterns were excavated beneath the castle. The defenses include double walls and towers named after the nations responsible for their maintenance, with the French Tower standing as the highest at 47.50 meters above sea level.

The castle withstood Ottoman attacks during the 15th century. In 1482, Prince Cem Sultan sought refuge here after a failed revolt against his brother, Sultan Bayezid II. Following the 1522 Siege of Rhodes, the castle fell under Ottoman control in 1523. The chapel was converted into the Süleymaniye Mosque and a minaret was added. Over the next four centuries, the fortress served as a military base and a prison, while certain reliefs and sculptures were removed to the British Museum during the 19th century.

During World War I, a French warship shelled the castle, destroying the minaret and damaging several towers. After a brief Italian occupation, Italian forces withdrew in 1921, and the castle remained empty for about 40 years. In the early 1960s, the Turkish government decided to convert the fortress into the Bodrum Museum of Underwater Archaeology, which later received a Special Commendation in the 1995 European Museum of the Year Award.

Today, the museum houses extensive collections including amphoras, ancient glass, the 14th-century BC Uluburun shipwreck, the Carian Princess exhibition, coin and jewelry halls, and recovered artifacts from various ancient shipwrecks. The castle grounds also feature a Mediterranean garden with local flora and roaming peacocks, while offering panoramic views of the city and surrounding bays from its towers.