Éternelle Notre-Dame: From Multidisciplinary Design to Longitudinal Evaluation of the Large-Scale Cultural Heritage Virtual Reality Experience

Background: When a blaze devoured the spire of Notre-Dame in April 2019, the cathedral’s future suddenly hinged on memory, measurement, and imagination. Purpose: Eternelle Notre-Dame responds by fusing sub-millimeter laser scans, archival iconography, and dramaturgical storytelling into a free-roam virtual-reality expedition that accommodates one hundred untethered visitors inside a 500 m² arena. Methods: This paper retraces the multidisciplinary pipeline behind that feat—from the historiographic choices that shaped a nine-scene narrative, through the ultra-low-latency networking stack that synchronizes Meta Quest headsets at 90 Hz, to the safety, accessibility, and comfort heuristics distilled from a three-week pilot deployment. We then triangulate ethnographic observations with 98 unsolicited online reviews collected over 42 months. Results: The analysis reveals how corporeal behavior, memorial imagination, and technological mediation intertwine to produce awe, vertigo, or scepticism in different audience segments. Conclusion: The findings not only validate crowd-scale heritage VR as a viable mode of public history but also surface open design tensions—between historicity and spectacle, agency and safety, immersion and reflection—that future cultural XR experiences must negotiate.