"The Structure of the Real Line" is a comprehensive non-fiction book that explores the structure of real numbers and their subsets. It highlights the developments in set theory over the past fifty years and their impact on the understanding of the real line. The author, Lev Bukovský, presents the content in a way that largely avoids the complete axiom of choice. The book is designed to be self-contained and covers all the necessary foundations of set theory, topology, measure theory, and descriptive set theory to minimize unnecessary applications of the axiom of choice. Special attention is given to the duality of measure and category, and several statements regarding properties of the real line that are considered undecidable in set theory are discussed. The appendix briefly explains the metamathematics behind set theory. Each section includes a series of exercises with additional results that deepen understanding.