Pergamon Bridge
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 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. The two intact tubes, which consist of supporting walls covered with barrel vaults, still serve their purpose to this day.
Pergamon
The Madradağ aqueduct was a ceramic pipe with a diameter of 18 cm which already brought water to the citadel from a source over 40 kilometres away in the Madradağ mountains at 1174 m above sea level in the Hellenistic period. Their significance for architectural history lies in the form of the last kilometres from the mountains through a 200 metre deep valley to the Akropolis. The pipe consisted of three channels, which ended 3 km north of the citadel, before reaching the valley, and emptied into a pool, which included a double sedimentation tank. This pool was 35 metres higher than the summit of the citadel. The pipe from the pool to the Acropolis consisted of only a single channel - a lead pipe pressurised to 200 mH2O. The water was able to cross the valley between the pool and the citadel with the help of this pressurised conduit. It functioned as a communicating vessel, such that the water rose to the height of the citadel on its own as a result of the pressurised pipe.