The Art Nouveau Path: Valuing Urban Heritage Through Mobile Augmented Reality and Sustainability Education

Cultural heritage is framed as a living resource for citizenship and education, although evidence on how in situ augmented reality can cultivate sustainability competences remains limited. This study examines the Art Nouveau Path, a location-based mobile augmented reality game across eight points of interest in Aveiro, Portugal, aligned with the GreenComp framework. Within a design-based research case study, the analysis integrates repeated cross-sectional student questionnaires (S1-PRE N = 221; S2-POST N = 439; S3-FU N = 434), anonymized gameplay logs from 118 collaborative groups, and 24 teacher field observations (T2-OBS), using quantitative summaries with reflexive thematic analysis. References to heritage preservation in students’ sustainability conceptions rose from 28.96% at baseline to 61.05% immediately after gameplay, remaining above baseline at follow-up (47.93%). Augmented reality items were answered more accurately than non- augmented reality items (81% vs. 73%) and involved longer on-site exploration (+10.17 min). Triangulated evidence indicates that augmented reality and multimodality amplified attention to architectural details and prompted debates about authenticity. Built heritage, mobilized through lightweight augmented reality within a digital teaching and learning ecosystem, can serve as an effective context for Education for Sustainable Development, strengthening preservation literacy and civic responsibility and generating interoperable cultural traces for future reuse.