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
The sanctuary was entered through a Propylon from the east, which led to a courtyard surrounded by stoas on three sides. In the centre of the western half of this courtyard, stood the Ionic temple of Demeter, a straightforward Antae temple, measuring 6.45 x 12.7 metres, with a porch in the Corinthian order which was added in the time of Antoninus Pius. The rest of the structure was of Hellenistic date, built in local marble and had a marble frieze decorated with bucrania. About 9.5 metres in front of the east-facing building, there was an altar, which was 7 metres long and 2.3 metres wide. The temple and the altar were built for Demeter by Philetaerus, his brother Eumenes, and their mother Boa.