I visited this WHS in Spring 2021 focusing first on the many lacklustre tumuli and the Kybele Sanctuary in the 8 locations close to Bergama town, Islamsaray and Kapikaya leaving the multi-layered (Hellenistic, Roman, Byzantium and Ottoman periods) city last.

Before driving up the steep road all the way up to the Acropolis, the Asklepeion and Red Hall (you can also take the cable car up if you don't want to drive to the top), I took in the interesting Red Hall/Temple of the Egyption Gods. When I visited, there were no apparent restrictions due to the COVID pandemic so I gladly visited these sites too before heading uphill to the Acropolis. There are old rusty brown metal UNESCO signs at most locations and the usual Turkish UNESCO WHS sign next to the Acropolis entrance.

The name Pergamon or Bergama means fortified area. Philetairos existed as a powerful kingdom from 283 BC. It fell under the Roman domination pursuant to the will of Attalus III in 133 BC, and the city started to reshape under the influence of Christianity when the Roman Empire began to lose power and divided in two. In the 8th century BC, Pergamon was exposed to Arab invasions and in the early 14th century it joined the Menteshe Beylik. The city was included in the Ottoman territories by Orhan Gazi in 1345 and the Turkish period began. The ancient city of Pergamon stands out with its successful urban planning despite the topographic difficulties.

The urban plan of Pergamon is divided in two: the upper city and the lower city. The upper city's significant monuments include the richly decorated palaces of kings planned with peristyle, the Temple of Athena, colossal statues of Roman Emperors Trajan and Hadrian, the Temple of Trajan, and the most important library of the ancient world housing 200,000 books written on parchment invented by the people of Pergamon. The most remarkable work of the city's architectural program is the Pergamon Altar or Altar of Zeus, built as a result of the decisive victory of Pergamon against the Galatians and Seleucids in Magnesia (180 BC) during the time of Eumenes II. The reconstruction of the altar dedicated to Zeus and Athena can now be admired in the Pergamon Museum in Berlin's Museum Island WHS.

The Acropolis of Pergamon was a culture and art hub of the ancient age. To the west of the Acropolis, the Selinus River (modern Bergamaçay) flows through the city, while the Ketios river (modern Kestelçay) passes by to the east. The theatre with a capacity of 10,000 people, the mobile stage building, and the Temple of Dionysus are the most obvious highlights of this WHS. However, another less visible highlight is the high pressure water line from Mount Madra at an altitude of 900 metres, made up of 240,000 earth pipes covering a length of 45 kilometres, built in the Hellenistic period to supply water on top of the Pergamon fortress, which was an great architectural achievement of Pergamon.

Pliny described the lower city of Pergamon as "the most famous and magnificent city of Asia Minor". In the lower city, there were rather social structures such as the sanctuaries of Hera and Demeter, the largest known gymnasium in the Hellenistic world, the lower agora, houses and shops. The city expanded out of the city walls to the foothills and then to the Bakircay Plains due to its growing population during the time of Eumenes II. The sanctuaries of Kizilavlu (Basilica) and Asklepeion are mong the most important structures of this expansion.

All in all I think Pergamon deserves its place on the WH list more for its importance in history than for the actual remains left in situ.