Bodrum (Turkish pronunciation: [ˈbodɾum]) (Ancient Greek: Ἁλικαρνᾱσσός Halikarnassós or Ἀλικαρνασσός Alikarnassós; Turkish: Halikarnas) is a district and a port city in Muğla Province, in the southwestern Aegean Region of Turkey. The name Bodrum derives from Petronium, named from the Hospitaller Castle of St. Peter. It is located on the southern coast of Bodrum Peninsula, at a point that checks the entry into the Gulf of Gökova, and is also the center of the eponymous district. The city was called Halicarnassus of Caria in ancient times and was famous for housing the Mausoleum of Mausolus, one of the Seven Wonders of the Ancient World. Bodrum Castle, built by the Knights Hospitaller in the 15th century, overlooks the harbour and the marina. The castle grounds include a Museum of Underwater Archaeology and hosts several cultural festivals throughout the year.