The ancient name of Bodrum is 'Halikarnassos'.

The city was named 'Petrium' after the city was dedicated to St. Peter, together with the castle called St. Peter's Castle. Over time, this name has been pronounced as 'petrum', then 'potrum' and finally 'Bodrum'.

The Mausoleum, one of the Seven Wonders of the World, was built in the city of Halicarnassus. The marble stones of the mausoleum, which was destroyed over time by the effects of earthquakes and invasions, were used in the construction of Bodrum Castle. Christian Knights built the castle in the 15th century. The construction was completed in a period of 100 years.