The Geometry of Love: Space, Time, Mystery and Meaning in an Ordinary Church by Margaret Visser, originally published in 2001, now available in hardback, paperback, and Kindle versions. Link is to Amazon page.
In this book, the historian and anthropologist Margaret Visser takes the reader through a Roman church, Saint Agnes Outside the Walls (Sant’Agnese fuori le Mura), exhaustively describing the architecture, history and current activities centered on this ancient structure. Sound boring? Oh believe me, it’s not. It is one of the most fascinating books I’ve ever read, and I’m so sorry that we didn’t visit this church when we went to Europe back in 1993. We’ll do so someday! I had read the book many years ago (it came out in 2001) and then again in 2013 when we went on our big driving trip to LA.