Ruins of the Ampitheater of Vespasian, from L'Encyclopedie Diderot et D'Alembert [18th century] (public domain image)

Architecture, Mysticism and Myth by W.R. Lethaby [1892]

This delightful book describes the symbolism of real-world architecture, as well as architecture described in fiction, myth and folklore. Lethaby believed that architecture reflected the macrocosm. He speculated that many of the seemingly ornamental details of classical buildings actually represented aspects of the land, the sea and the sky. This is one of those books like the Golden Bough or the White Goddess (albeit shorter and a less challenging read) that will turn you on to the mythopoetic side of reality, no matter whether you agree with its conclusions.