The Pergamon Bridge is a Roman substruction bridge over the Selinus river (modern Bergama Çayı) in the ancient city of Pergamon (today Bergama), modern-day Turkey. The 196 m (643 ft) wide structure, the largest of its kind in antiquity, was designed during Hadrian's reign (AD 117–138) in order to form a passageway underneath a large court in front of the monumental "Red Basilica" temple complex.