What are the most interesting and least well-known Roman aqueduct facts?

The Romans used aqueducts to transport water from distant sources into the cities and agricultural lands. The first Roman aqueduct was built to supply a water fountain at the cattle market in the city.

The Romans built their aqueducts from a combination of brick and stone, to which they added a special volcanic cement known as pozzuolana. They built the aqueducts above the ground so nothing could obstruct their paths. When a natural obstacle appeared, the Romans simply built the aqueduct over it or cut through stone to clear the path. Some wealthy Romans had their own private aqueducts to bring water to their remote villas.