Aqua Virgo
About
Aqueduct completed by Agrippa in 19 BCE, running c. 20.5 km mostly underground from springs east of Rome, built specifically to feed Agrippa's Baths and the pools/canal (Euripus) of the Campus Martius. Fully operational and delivering water into central Rome in 117 CE; its terminal distribution point in antiquity lay near where the Baroque Trevi Fountain now stands (the fountain itself is an 18th-century addition, included here only to mark the ancient terminus location).
What happened here
Water arrives day and night and never stops. The channel runs mostly underground, following a shallow gradient measured out with a levelling instrument over tens of miles, and it goes up on arches only where the ground drops away. Inspection shafts sit at intervals; gangs work the line constantly, cutting out the lime crust that thickens on the walls and narrows the flow. At the town end the water is divided in a distribution tank — public fountains first by law, then baths, then private houses whose owners have paid for a pipe of a fixed and stamped size. Illegal tappings are a permanent scandal. What arrives is not stored but runs continuously, and the overflow flushes the drains.
Sources
Roman Maps shows the empire frozen at 11 August 117 CE, the day Trajan died — its moment of greatest territorial extent. Explore the full map →