"Cosmological Crossroads" is a specialized book that has emerged from lectures at a summer school on cosmology. It is aimed at postgraduates and non-specialized researchers from various disciplines, including mathematical physics and observational astrophysics. The book seeks to bridge the gap between the fundamental textbook content of cosmology and the latest research findings. It provides a modern reference for experienced researchers in the fields of classical and quantum cosmology, making it a valuable tool for anyone looking to engage with the complex topics of cosmology. The authors, Spiros Cotsakis and Eleftherios Papantonopoulos, have created a work that addresses both theoretical and practical aspects of cosmology, thus appealing to a wide readership.