The ancient way through Constantinople from Black Sea region consists of many important ancient site. All of them had strategical and military importance in the route. One of them was Prusias ad Hypium ancient site;
This site was constructed in 3rd century AD with the name of Hypios. Then the name of the city had changed as Kieros. When Btyhnian King Prusias I conquered the site, the name of the site had changed as Prusias in the name of the king. Many monumental pieces were built in the site in various periods including aqueducts from Roman period.
It is located between Marmara and Western Black Sea. It seems that it was as important as Ephesus. Also it had a military base in the site.