Bodrum Castle (Castle of St Peter) and the Museum of Underwater Archaeology

Commanding the rocky headland between Bodrum's eastern and western bays, the Castle of St Peter (Bodrum Kalesi) was begun in 1402 by the Knights Hospitaller of St John (headquartered on Rhodes) on the site of ancient King Mausolus's palace and an earlier Seljuk fort. When a series of earthquakes finally toppled the nearby Mausoleum at Halicarnassus, the Knights quarried its green volcanic stone blocks and white Proconnesian marble reliefs to fortify the castle walls, creating five distinct national towers: the French, English, Italian, German and Snake Towers. After Sultan Suleiman the Magnificent captured Rhodes in 1522, the castle surrendered peacefully to the Ottomans and a minaret was added to the Gothic Knights' chapel in the courtyard.

The Museum of Underwater Archaeology (Sualtı Arkeoloji Müzesi)

Following a comprehensive multi-year structural restoration, Bodrum Castle houses one of the most important maritime museums in the world. Beginning in the late 1950s and 1960s, local Bodrum sponge divers led archaeologist George Bass and the Institute of Nautical Archaeology (INA) to scores of ancient amphora-laden shipwrecks lying on the Aegean and Mediterranean seabed, founding the modern science of underwater archaeology. Do not miss four extraordinary halls inside the castle ramparts:

• The Uluburun Shipwreck (14th Century BC, Late Bronze Age): sunk off Kaş around 1300 BC, this is one of the oldest and richest royal cargoes ever raised from the sea. Inspect ten tonnes of Cypriot oxhide copper ingots, a tonne of tin, raw cobalt-blue glass ingots, Canaanite amphorae, elephant and hippopotamus ivory, Baltic amber and a solid gold scarab inscribed with the name of Egyptian Queen Nefertiti.
• The Serçe Limanı Glass Wreck Hall (1025 AD): inside a dimly lit hall, see the reconstructed hull of an 11th-century Byzantine-Islamic merchant ship that sank carrying three tonnes of Islamic glass cullet and hundreds of intact blown glass vessels.
• The Carian Princess Hall (Ada of Caria): displays the golden diadem, necklaces and skeletal reconstruction of a 4th-century BC Hekatomnid royal woman excavated in Halicarnassus in 1989.
• The Amphora Collection and English Tower: hundreds of two-handled clay transport jars stacked chronologically across 2,000 years of wine and olive-oil trade, plus panoramic views from the crenellated walkways over both bays. Arrive at early in the morning when gates open (closed Mondays in low season; Museum Pass Turkey is valid).