Pergamum was an ancient Greek city founded by colonists on the Aegean coast of Anatolia. The city became the capital of the Kingdom of Pergamon during the Hellenistic period, under the Attalid dynasty, 281–133 BC. This Hellenistic city was the center of culture, commerce and medical with its philosophers, scientists and artists like Galen (131-210 AD)., boasting an outstanding library, a famous school of sculpture, excellent public buildings and monuments and several art works at good taste.
Pergamum was the most eminent center of culture in the Hellenistic period. It has inhabited since the times of Troy and witnessed two great ancient civilisations the Hittites and the Greeks. The site is also known as the place where parchment was invented.
In the Roman period, Pergamum played an important role in the early history of Christianity. It was also numbered among the Seven Churches of Revelation.Today, the main sites of ancient Pergamon are to the north and west of the modern city of Bergama. 
Asceplion, the first edifice to visit,  was a sanctuary and a medical complex out of the city. The complex was built in the 4th Century in the name of Aesculapius, meaning the god of Health and Medicine and provided healing and cure for many philosophers, scientists etc.
Pergamon's library on the Acropolis (the ancient Library of Pergamum) is the second of the three famous ancient libraries in the ancient Greek civilization.
The finest altar ever built can be accepted as the Zeus Altar in Pergamum, dating back to 180 BC, which stands in its own precinct but, most unusually, without a temple.
The Sanctuary of Athena dedicated to victory-bringing Athena by King Eumenes, The Temple of Trajan dating back to 2th Century AD, The Theater in the acropolis of Pergamum which is the steepest raked Hellenistic theater in the world, are well-worth places to visit to feel the magic of the history.