This chapter analyzes the Expiatory Temple of the Blessed Sacrament in Guadalajara, one of the most complex and emblematic Neo-Gothic constructions in Mexico. Conceived in 1897 as part of the Catholic Church’s strategy to reaffirm its presence in the public sphere, its construction spanned 75 years and involved multiple architects, engineers, artisans, and ecclesiastical authorities. The original project, drafted by engineer Salvador Collado Jasso, was revised by Adamo Boari and later reinterpreted by Ignacio Díaz Morales, who directed the works from 1927 to 1972. The temple’s formal language combines Italian Gothic and Umbrian Romanesque influences with structural innovations drawn from industrial engineering. The Italian sculptor Adolfo Octavio Ponzanelli was responsible for the extensive decorative program, including tympana, Stations of the Cross, and a monumental rose window. The building also incorporates works by Mexican artists such as Alfonso de Lara Gallardo (stained glass) and Xavier Corberó (bronze altarpiece). The temple functioned not only as a space of perpetual Eucharistic adoration but also as a symbol of Catholic resilience amid revolutionary and anticlerical pressures. Its architectural and liturgical program makes it a unique case of religious modernity shaped through historicist language and local reinterpretation.