Pergamon
UNESCO World Heritage Site (Pergamon And Its Multi Layered Cultural Landscape, 2014); Hellenistic Royal Capital And Roman Provincial City · Bergama, Izmir
Pergamon was a Hellenistic kingdom's capital before it was a Roman city, and its rulers built upward: the acropolis stacks temples, palaces, a library and a theatre up a hill of 335 metres, and the theatre is the steepest of the ancient world, eighty rows dug into a slope so severe that standing at the top is genuinely alarming. The library here held two hundred thousand scrolls and rivalled Alexandria's, and when Egypt cut off the papyrus supply, Pergamon's answer was to refine treated animal skin - parchment, pergamena, named after the place. The Altar of Zeus is famous and is not here; it was excavated by German archaeologists and reassembled in Berlin, so what you see is a foundation and a view. Two more sites make up the whole: the Asklepion, a Roman healing sanctuary where Galen practised, and the Red Basilica in the town, a vast temple to Egyptian gods later turned into a church of Revelation.
Zafer Mahallesi, Akropol Caddesi, Bergama, Bergama, Izmir, Turkiye
The acropolis, the Asklepion and the Red Basilica are separate sites with their own gates and tickets, open daily with longer summer hours. The cable car to the acropolis runs through the day and stops in high wind, which happens. Winter hours are much shorter and the last cable car up is early. Check all three before planning a single day around them.