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
A two-story stoa surrounding the temple on three sides was added under Eumenes II, along with the propylon in the southeast corner, which is now found, largely reconstructed, in the Pergamon Museum in Berlin. The balustrade of the upper level of the north and east stoas was decorated with reliefs depicting weapons which commemorated Eumenes II's military victory. The construction mixed Ionic columns and Doric triglyphs (of which five triglyphs and metopes survive). In the area of the sanctuary, Attalos I and Eumenes II constructed victory monuments, most notably the Gallic dedications. The northern stoa seems to have been the site of the Library of Pergamon.