City in Bithynia 8 km N of Duzce, which lies midway between Istanbul and Ankara, and on the road from Duzce to Akcakoca on the Black Sea. It was an important city on the road from Nicomedia (Izmit) to Amastris (Amasra) in Pontos, and lay E of the Hypios river.
The site is on a defensible hill at the foot of Mt. Hypios, and is mentioned by Pliny and Memnon. According to the latter, King Prusias I conquered Kieros and changed its name to Prusias. When the city was conquered by the Romans in 74 B.C. it consisted of four phylai; it flourished under Roman rule, and inscriptions indicate that it had 12 phylai in the 2d c. A.D. Hadrian, Caracalla, and Elagabalus visited it, and in the 4th c. it became a bishopric. Georgios, bishop of Prusias ad Hypium, was present at the Council of Nicaea, and another bishop, Olympios, attended the Council of Calchedon in 451.
Remains are of the Roman period and Roman walls surround the site. The S and W walls and a S gate called Baltali Kapi are still standing; they incorporate many earlier inscriptions. The theater, 100 by 74 m, probably dates from the 2d c. A.D. Most of the cavea is standing, and the scaenae frons and parodoi are visible. A three-arched bridge, 10 m long, outside the walls to the W, was intact until recently, when a flood ruined the pavement. A colonnaded street runs SE from the bridge; carved entablatures, arches, pediments, pavements, and drains are still visible. Pavement mosaics, now covered, have been found S of the city outside the wall. They include scenes of Achilles and Thetis and of Orpheus with the Seasons.
Buildings of the early Ottoman period include a bath and an aqueduct. Many inscriptions, architectural fragments, bomoi (especially the funerary bomos of an Athenian actor), and a garland sarcophagus can be seen in the museum depot. Other finds are in the Istanbul Archaeological Museum, including a bust of a boy, and statues of Tyche, a philosopher, and a seated woman. (N. FIRATLI) Wikidata ID: Q377863
Info: Princeton Encyclopedia
(Princeton Encyclopedia of Classical Sites, from Perseus Project)