Aqueduct (bridge)

They may take the form of tunnels, networks of surface channels and canals, covered clay pipes or monumental bridges.

[3] In the seventh century BCE, the Assyrians built an 80 km long limestone aqueduct, which included a 10 m high section to cross a 300 m wide valley, to carry water to their capital city, Nineveh.

Roman aqueducts set a standard of engineering that was not surpassed for more than a thousand years.

During the Industrial Revolution of the 18th century, navigable aqueducts were constructed as part of the boom in canal-building.

This allowed vessels to cross at high and low levels while conserving water that would be lost in the operation of locks.