How the Greek influence is still visible in Side
Greeks that live in Turkey are called "Rumlar", which means "Romans". This is derived from the term "Rhomioi", which was used by Middle-Ages Greeks; these people believed that they would inherit the Roman Empire. Greeks have lived in Turkey since the middle of the second millennium BC, but following social upheaval during the collapse of the Bronze age, it was settled heavily by both Aeolian and Ionian Greeks.
Numerous colonies were founded on the coast of Asia Minor during the 8th-6th centuries BC, and they were founded by both settlers and mainlanders. Byzantium (later Istanbul / Constantinople) was founded in the 7th century BC. Following a conquest by Alexander the Great, the remainder of Asia Minor was open for settlement, but upon his passing, the area was ruled by any number of different kingdoms. A period of peace followed, and the local language was soon overtaken by Greek.
Asia Minor (including the city of Side) was one of the first places to see the spread of Christianity, and by the end of the fourth century AD, it was mostly Greek-speaking and Christian. For the next six centuries, the area would be the center of the Hellenic culture, while the mainland Greeks endured multiple invasions by barbarian tribes and suffered a steep decline. Fast forward to the time after WWI, when Side and the entire area figured into the Megali Idea, which was the push for liberation of all lands inhabited by Greeks., and set forth the idea of a successor to the Byzantine Empire.
During that time, the Ottoman government started a very violent campaign against Turkish Greeks. Thousands were massacred or forced to march to their deaths, or were expelled from Turkey. According to multiple sources, several hundred thousand Turkish Greeks died during the time after the first World War. Some refugees, especially those from the east, fled to Russia.