I’ve read it multiple times, each time gain understanding of how things work.

Great reviews by others:
Apparently L. Sprague de Camp was a science fiction writer who also liked debunking pseudo-scientific claims in his non-fiction books, this book as I have since learned was one of his most popular. I enjoyed reading it very much, the history and detail is so rich and well written I feel it would be impossible to dislike. I would never have guessed it was written in 1963.
Every family has one. That loud-mouth who insists that because he doesn’t know how something was built, it had to be aliens. Or Atlantis. Or Superman. Anything other than pure human ingenuity.

This book is perfect for those people. (Or just to read when ignoring those people.) It describes how the ancient engineers built those amazing things without using a single scrap of alien technology. Even better, it shows how some of the traces of those things remain in our building today, such as the shape of banks and the fluting in columns.

Read it. And then tell that loud-mouth what *really* happened!
The Ancient Engineers, L. Sprague de Camp, ISBN 0-88029–456-6