The origin of the castle of Marmaris is controversially discussed among archaeologists. It is believed that the fortress was first built during the "Ionian colonization" (around 1044 BC) and later renovated for the first time during the reign of Alexander the Great. It is considered certain that the Byzantines maintained a small garrison in the castle.

However, there is evidence that the castle was renovated and extended under Sultan Süleyman the Magnificent. He had gathered his armada in the protected bay of Marmaris.
According to a local legend, the name of the town means "four hanged architects". It derives from the history of the formation of the formative castle. In 1522, after his victory over Rhodes, the then Sultan Suleyman the Magnificent ordered his four architects to build a castle that could still be seen in Rhodes. A relatively small castle was built on the basis of the money available, which so infuriated the Sultan that when he returned from an expedition to Rhodes, he was said to have proclaimed "Mimar äs!". Which means "hang the architects"! But there is no documented source for this.

In 1958 Marmaris was almost completely destroyed by an earthquake. As one of the few historical buildings, Marmaris Kalesi Castle was hardly damaged. Until the 1970s, the remaining rooms served as stables and storage rooms. Between 1980 and 1990 the castle was restored and converted into a museum. Today Marmaris has become an expensive tourist hotspot. The castle is a popular destination for international tourists