David Macaulay takes us on a visual journey through a city's various support systems by exposing a typical section of the underground network and explaining how it works. We see a network of walls, columns, cables, pipes and tunnels required to satisfy the basic needs of a city's inhabitants.

""A straightforward yet fascinating description of the labyrinth beneath the feet of any city dweller. And what a complex covered world David Macaulay reveals! He invents an intersection of two streets and proceeds to show what we all might find if we dared to descend through that Alice-in-Wonderland manhole."" The New York Times