This must be the most magnificent ancient city ruins I've ever visited.

Pergamon, known as Pergamon in ancient times, the city of Asclepius the healing god, and hometown of Galen, the most famous physician and theorist of ancient Rome. From being the "Second Athens" of the Attalid dynasty during the Hellenistic period to becoming a "metropolis" during Hadrian's era. It boasts the steepest and most precipitous theater in the ancient world (Figure 1), which feels even more spectacular than the theaters at the Acropolis of Athens and Delphi in Greece, with terrain comparable to the ancient theater in Taormina, Sicily, Italy. Above the theater stands the massive architectural structure of the Trajan Temple (Figures 2, 3), along with the palace ruins of Hellenistic kings. The most famous structure on the Acropolis is undoubtedly the Hellenistic "Altar of Zeus," now reduced to ruins (Figures 5, 6, 7). Its exquisite frieze depicts the ancient gods' "Battle of the Giants," a masterpiece of Hellenistic art. The frieze panels and some decorative elements were taken to Berlin by a German archaeological team in the 19th century, becoming the most important collection of the Pergamon Museum. There are also the temples of Asclepius, Dionysus, and Athena at the foot of the hill... and the "Red Basilica," the largest structure in the Greek world during ancient Roman times, likely sponsored by Emperor Hadrian (Figure 8). The Pergamon Acropolis, with its architectural diversity and rigorous layout, became a model of classical urban expansion planned in stages. After the end of the classical era, the city experienced several rises and falls. During the Byzantine period, walls and churches were built, and in the 13th and 14th centuries, it suffered Seljuk raids and earthquakes. By the Ottoman period, the Acropolis and other ancient structures were abandoned, and a series of settlements were established at the foot of the hill. Pergamon was inscribed on the UNESCO World Heritage List for its layered cultural landscape and historical significance, with the following evaluation: Rising above the plains of Turkey's Aegean region, the Pergamon Acropolis was the capital of the Hellenistic Attalid dynasty and a major academic center of the ancient world. Monumental temples, theaters, stoas or arches, gymnasiums, altars, and libraries were built on the steep slopes of the hill, surrounded by a massive wall. Later, the city became the capital of the Roman province of Asia, renowned for its Asclepeion healing center. The summit of the Acropolis presents a multi-layered landscape featuring remains from the Roman, Byzantine, and Ottoman empires, overlooking the western Anatolian plains.