Technology
The ancient Romans also had a complex system of aqueducts, which were used to transport water across long distances. The first Roman aqueduct was built in 312 BCE. The eleventh and final ancient Roman aqueduct was built in 226 CE. Put together, the Roman aqueducts extended over 450 kilometers, but less than seventy kilometers of this was above ground and supported by arches.
Varna
The main aqueduct of Odessos was recently discovered during rescue excavations north of the defensive wall. The aqueduct was built in three construction periods between the 4th and the 6th centuries; in the 4th century the aqueduct was built together with the city wall, then at the end of the 4th to early 5th centuries when a pipeline was laid inside the initial masonry aqueduct. Thirdly in the 6th century an extra pipeline was added parallel to the original west of it and entered the city through a reconstruction of the fortress wall.