In the learning environment of cultural heritage sites, mobile augmented reality (MAR) technology, as an emerging innovation, is widely employed to enhance visitors’ learning experiences and interactive engagement. This paper focuses on Mandarin’s House as a case study, exploring how MAR technology can cultivate depth and a sense of participation at cultural heritage sites, thereby enriching visitors’ informal learning experiences based on theories of hedonic experience, mindfulness, and pleasurable technology design. Through case studies, interviews, and literature analysis, we systematically evaluate the impact and effectiveness of MAR technology in informal learning at Mandarin’s House. The research findings indicate that MAR technology not only enhances visitors’ understanding and interactive experiences of cultural heritage but also fosters dynamic participation in informal learning and the formation of personalized learning pathways. This study deepens the understanding of the mechanisms by which MAR technology operates in informal learning within cultural heritage contexts and provides empirical support and methodological insights for the application of educational technology in similar environments in the future.