Pergamon
Pergamon's other notable structure is the great temple of the Egyptian gods Isis and/or Serapis, known today as the "Red Basilica" (or "Kızıl Avlu" in Turkish), about south of the Acropolis at (39 7' 19" N, 27 11' 1" E). It consists of a main building and two round towers within an enormous "temenos" or sacred area. The temple towers flanking the main building had courtyards with pools used for ablutions at each end, flanked by stoas on three sides. The forecourt of the Temple of Isis/Sarapis is still supported by the Pergamon Bridge, the largest bridge substruction of antiquity.
Pergamon
From the beginning of the reign of Philetairos, civic events in Pergamon were concentrated on the Acropolis. Over time the so-called 'Upper agora' was developed at the south end of this. In the reign of Attalos I, a Temple of Zeus was built there. To the north of this structure there was a multi-story building, which propbably had a function connected to the marketplace. With progressive development of the open space, these buildings were demolished, while the Upper Agora itself took on a more strongly commercial function, while still a special space as a result of the temple of Zeus. In the course of the expansion of the city under Eumenes, the commercial character of the Upper Agora was further developed. The key signs of this development are primarily the halls built under Eumenes II, whose back chambers were probably used for trade. In the west, the 'West Chamber' was built which might have served as a market administration building. After these renovations, the Upper Agora thus served as a centre for trade and spectacle in the city.