Pergamos was referred to in the book of Revelation as "where satan's seat is" (Rev 2:13), most likely in reference to the temple of Augustus and prominence in the practice of emperor worship.  The temple to Zeus at the top of the Acropolis, which now resides in the Pergamon Museum in Berlin, may also be the reference to "satan's seat".  

“I know your works and where you dwell, where Satan’s throne is...’’ (1 Revelation 2:13)

In modern day Bergama, a town located in the northern Aegean coast of Turkey, an extensive archaeological preserve is open to the public, a tribute to what was once dubbed "the most famous and magnificent city of the Asia Minor."  A city which, despite its splendor, carried an undertone of spiritual darkness.  The martyrdom of Antipas is specifically referred to in the letter to the church of Pergamos in Revelation 2:13. He was the bishop of the church at Pergamos, whose refusal to acceed to the cult of emperor worship and proclaim Caesar's divinity earned him a death sentence. According to church tradition, Antipas was placed inside of a bronze bull, and burned alive.

Main Attractions

Acropolis

The acropolis of Pergamos sits over a thousand feet above the valley below.  Modeled after the Acropolis in Athens, it was the design of the builders of the city to create another main cultural center in the ancient Greek world, like Athens.

Pergamon Library

The library at Pergamos was one of the most prominent libraries in the ancient world, housing approximately 200,000 volumes. Today, the ruins consist of portions of the walls and foundation of this once prominent building.

 Theatre

A steep stadium can be seen to this day, built upon the steep slope beneath the acropolis.  With the capacity to seat 10,000 people, the theatre was constructed in such a manner that any spectator could hear so much as a whisper from the stage below.

Temple of Trajan

On the Acropolis are some prominent reconstructed pillars which once formed the temple of Trajan, build in the second century AD.

References:

https://hometurkey.com/en/destinations/bergama-pergamon

https://www.bibleplaces.com/pergamum/

https://www.biblicalarchaeology.org/daily/biblical-sites-places/biblical-archaeology-sites/pergamon-2/

https://turkeytravelplanner.com/go/Aegean/Bergama/sites/acropolis.html