About the Aqueducts
Aqueducts were used to carry water to towns or cities. The waste goes to a sewage system, then to other bodies of water. Most of them are still standing 2,000 years later(today).
Slaves and paid laborers built them out of bricks. They used lots of arches. They could use stone, clay, or lead pipes. If a mountain was in the way they built right through it.