Roman aqueduct
Rome's first aqueduct was built in 312 BC, and supplied a water fountain at the city's cattle market. By the 3rd century AD, the city had eleven aqueducts, sustaining a population of over a million in a water-extravagant economy; most of the water supplied the city's many public baths. Cities and towns throughout the Roman Empire emulated this model, and funded aqueducts as objects of public interest and civic pride, "an expensive yet necessary luxury to which all could, and did, aspire".
History of Athens
He built the first aqueduct as an underground tunnel. Its sources were most likely on the slopes of Mount Hymettos and along the Ilissos river. It supplied, among other structures, the fountain house in the southeast corner of the Agora, but it had a number of branches. In the 4th century BC it was replaced by a system of terracotta pipes in a stone-built underground channel, sometimes called the Hymettos aqueduct; many sections had round, oval or square access holes on top of about .
Pipe segments of this system are displayed at the Evangelismos and Syntagma Metro stations.