Catherine Chambers 
Stickmen’s Guide to Cities in Layers [PDF ebook] 

Perch on top of a skyscraper with the Stickmen, then descend to street level and travel below to see all the layers of a city. But beware, some layers are smellier than others! Follow the Stickmen to land on a helipad, ride in a double-decker underground subway, and view a giant lump of fat in a sewer. The Stickmen unveil the hidden systems that keep a city lit up, networked, and clean, and reveal fascinating facts and statistics along the way.