Bodrum's history runs much deeper than its reputation as a party town suggests. The Castle of St Peter is the obvious starting point — a 15th-century crusader fortress that now houses one of the world's best museums of underwater archaeology. The Mausoleum of Halicarnassus, or what remains of it, is a short walk inland. There is not much left above ground, but the site museum explains its former scale.
Beyond the ruins, Bodrum is a base for boat trips along the coast, diving, and exploring the quieter peninsula villages to the west.