Macaulay is perhaps best known for The Way Things Work, a highly-illustrated mammoth-obsessed and remarkably comprehensive introductory guide to technology for children. I remember it in my childhood, and it may be featuring in my son's birthday today.
While looking around, I discovered a few other books written by Macaulay, including this one. It covers the underground infrastructure of our cities - foundations, sewers, all manners of pipes and ducts, etc. I'm afraid I had to have it.
In the longer term, I'm sure the children will enjoy it. Right now, it's all mine. It is, fundamentally, a children's book. However, it's not dumbed down, an adult can happily learn from it, and the illustrations are lovely. I'd particularly recommend it to a 25-year-younger me.