The ancient city of Mylasa (today Milas) was one of the most important cities in the interior of Caria. In the 5th century B.C. it briefly belonged to the Attic Sea Alliance and was the seat of the Carian rulers of the Hekatomnid dynasty in the 4th century before Mausolos moved his seat around 360 B.C. to Halicarnassus, today's Bodrum.

Roman tomb from the 1st century B.C. in the style of the mausoleum of Halicarnassus

Mylasa can probably be equated with the Hittite city of Mutamutašša. In Hellenistic times Mylasa belonged successively to different empires. It was badly devastated during the invasion of the Parthians in 40 B.C. and had no great significance during the Roman imperial period, even though it became the seat of a Christian bishop in late antiquity.

The double axe gate is named after the double axe carved into the end stone of the archway. The archaeologists are still arguing about the former function of the gate. Was it part of the city wall, was it a triumphal gate built during an imperial visit or was it built for a completely different reason?