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 Altar
Up until the second half of the 20th century it had been assumed by some scholars that the altar was endowed in 184 BC by Eumenes II after a victory over the Celtic Tolistoagian tribe and their leader Ortiagon. In the meantime, later datings relating the altar to archaeological findings and historical events are under discussion. It is not imperative to connect the altar endowment with specific military events such as the Roman victories over Antiochos III in 184 BC in alliance with Eumenes II, or Eumenes II's own victory over the Galatians in 166 BC. Investigation of the altar's construction and friezes has led to the conclusion that it was not conceived as a monument to a particular victory. The design of Pergamene victory monuments is known from the literature and monument relics. The most famous are Roman copies of bronze statues of the "Great Gaul", representations of defeated Celts after the victory of Attalos I over the Tolistoagians, or reliefs showing booty weapons from the halls of the Pergamene Athena sanctuary, which was dedicated by Eumenes II to the goddess who brought victory after the triumph over the Seleucids and their allies in 184 BC.