Callatis Fortress Wall defined the area of the ancient Callatis city which today is Mangalia. The wall was built in two phases – the first one at the end of the 4th century B.C., when it was erected by the Greek settlers and the second in the 2nd century A. D., under the Roman occupation. It had the purpose of protecting the main buildings of the city: the temples, the squares, public institutions, etc. It is a historic monument.