Oescus

Oescus (later Ulpia Oescus) was a major Roman city on the Danube near modern Gigen in northern Bulgaria, originating as a Thracian settlement from the Late Bronze Age. The Roman Legio V Macedonica was stationed here from 10 to 101 AD, and Emperor Trajan granted it colony status between 106-112 AD. At its peak the city covered 280,000 sq m with an estimated 100,000 inhabitants. Emperor Constantine built a 2.5 km bridge connecting it to Sucidava across the Danube, opening in 328 AD. Excavations uncovered a famous 3rd-century mosaic depicting Menander's lost play "The Achaeans" and an aula regia decorated with 14 types of rare marble.