Settlers from Cyme (Cumæans) in Aeolis, an ancient region of northwestern Asia Minor, founded the city in the seventh century BC. Possessing a good harbor for small-craft boats, Side's natural geography made it the most important place in Pamphylia – the region in the south of Asia Minor between Lycia and Cilicia, from the Mediterranean to Mount Taurus. This location made Side one of the most important trade centers in its time. Today, as in yesteryear, the ancient city of Side is situated on a small north-south peninsula about 1 km long and 400 m across.
Next to no information exists concerning Side under Lydia and Persian Empire sovereignty. Nevertheless, the fact that Side minted its own coins during the 547 BC while under Persian dominion, shows that it still possessed a great measure of independence.
Alexander the Great occupied Side without a struggle in 333 BC. Alexander left only a single garrison behind to occupy the city. This occupation, in turn, introduced the people of Side to Hellenistic culture of the Greek Civilization, which flourished from the fourth century to the first century BC. After Alexander's death, Side fell under the control of one of Alexander's generals, Ptolemy I Soter, who declared himself king of Egypt in 305 BC. The Ptolemaic dynasty controlled Side until it was captured by the Seleucid Empire in the second century BC. Yet, despite these occupations, in the following years of the second century BC, Side managed to preserve some autonomy, grew prosperous, and became an important cultural center.
In 190 BC a fleet from the Greek island city-state of Rhodes, supported by Rome and Pergamum, defeated the Seleucid King Antiochus the Great's fleet, which was under the command of the fugitive Carthaginian general, Hannibal. The defeat of Hannibal and Antiochus the Great meant that Side freed itself from the overlordship of the Seleucid Empire. The embarrassing Treaty of Apamea (188 BC) forced Antiochus the Great to abandon all European territories and to cede all of Asia Minor north of the Taurus Mountains to Pergamum. However, the dominion of Pergamum only reached de facto as far as Perga, leaving Eastern Pamphylia semi-free. This led Attalus II Philadelphus to construct a new harbour in the city Attalia (the present Antalya), even though Side already had an important harbour. Between 188 and 36 BC Side minted their own money, tetradrachms showing Nike and a laurel wreath (the sign of victory).
The consul Servilius Vatia defeated these brigands in 78 BC and later the
Roman general Pompey in 67 BC, bringing Side under the control of the Roman Empire. Side's second peak period started around 2C BC when it established and maintained a good working relationship with the Roman Empire.
Emperor Augustus reformed the state administration and placed Pamphylia and Side in the Roman province of Galatia in 25 BC, after the short reign by the king Amyntas of Galatia between 36 and 25 BC. Side began another prosperous period as a commercial center in Asia Minor through its trade in olive oil. Its population grew to 60,000 inhabitants. This period would last well into the third century AD. Side established itself as a slave-trading center in the Mediterranean. Its large commercial fleet engaged in acts of piracy. Wealthy merchants paid for such tributes as public works, monuments, and competitions as well as the games and gladiator fights. The significance of this period for Side is evident in its ruins today. Most of the present-day ruins found in Side date from this period of prosperity.
In the twelfth century, Side temporarily established itself once more as a large city. An inscription found on the site of the former ancient city shows a considerable Jewish population in early Byzantine times. However, Side was abandoned again after being sacked. Its population moved to Antalya and Side became known as Eski Adalia or Old Antalya and was buried.
The great ruins are among the most notable in Asia Minor. They cover a large promontory where a wall and a moat separate it from the mainland. During medieval times, the wall and moat were repaired and the promontory houses a wealth of structures.
There are colossal ruins of a theater complex, the largest of Pamphylia, built much like a Roman amphitheater that relies on arches to support the sheer verticals. The Roman style was adopted because Side lacked a convenient hillside that could be hollowed out as in the usual Greek fashion more typical of Asia Minor. The theater is less well preserved than the Aspendos theater, but it is almost as large, seating 15,000 - 20,000 people. With time and the shifting of the earth, the scena wall has collapsed over the stage and the proscenium is in a cataract of loose blocks. It was converted into an open-air sanctury with two chapels during Byzantine times (5-6th c.)
The well preserved city walls provide an entrance to the site through the Hellenistic main gate (Megale Pyle) of the ancient city, although this gate from the second century BC is badly damaged. Next comes the colonnaded street although the marble columns once there do not exist anymore. All that remains is a few broken stubs near the old Roman baths. The street leads to the a public bath, restored as a museum displaying Roman period statues and sarcophagi. Next is the square agora with in the middle the remains of the round Tyche and Fortuna temple (2nd c. BC), a periptery with twelve columns. In later times it was used as a trading center where pirates sold slaves. The current remains of the theatre, which was used for gladiator fights and later as a church, and the monumental gate date back to the 2nd century. The early Roman Temple of Dionysus is near the theater. The fountain gracing the entrance is restored. At the left side are the remains of a Byzantine Basilica. A public bath has been restored
The remaining ruins of Side include three temples, an aqueduct, and a nymphaeum. Side's nymphaeum – a grotto with a natural water supply dedicated to the nymphs – was an artificial grotto or fountain building of elaborate design.
Turkish archaeologists have been excavating Side since 1947 and intermittently continue to do so.
It was a favorite spot for watching the solar eclipse of March 29, 2006.