Rotunda is one of the most emblematic historic buildings of Thessaloniki, built around 306 AD. by the Roman Emperor Galerius as Mausoleum. It was transformed into a Christian church during the reign of Emperor Theodosius I. In 1590 the building was converted into a mosque by the Turks. They added a minaret of 35.85 meters height, which is the only one of the Ottoman Rule period still standing in Thessaloniki.