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
Pergamon is a good example of a city that expanded in a planned and controlled manner. 
Philetairos transformed Pergamon from an archaic settlement into a fortified city. He or his successor Attalos I built a wall around the whole upper city, including the plateau to the south, the upper agora and some of the housing - further housing must have been found outside these walls. Because of the growth of the city, the streets were expanded and the city was monumentalised.
Under Attalos I some minor changes were made to the city of Philetairos.
During the reign of Eumenes II and Attalos II, there was a substantial expansion of the city. A new street network was created and a new city wall with a monumental gatehouse south of the Acropolis called the Gate of Eumenes. The wall, with numerous gates, now surrounded the entire hill, not just the upper city and the flat area to the southwest, all the way to the Selinus river. Numerous public buildings were constructed, as well as a new marketplace south of the acropolis and a new gymnasion in the east. The southeast slope and the whole western slope of the hill were now settled and opened up by streets.