the.com/aqueduct
Rome's water highways ran on gravity alone, sloping a few inches per mile to perfection.
still standingSegovia's aqueduct held water until the 1970s
no mortarStones stay stacked by gravity and friction
daily haulRome delivered over a million cubic meters daily
slow dropSome sloped just 34 centimeters per kilometer
undergroundMost ran hidden below ground, not arches