We present insights from the design and development process of Singapore Heritage Trails (SGTrails), a location-aware mobile application that supports users’ exploration of sites of heritage and cultural value. Our findings are based on (a) a survey to understand users’ perceptions about the role of technology, (b) a field study to compare a prototype version with a paper guide, and (c) analysis of implementation, initial adoption, and usage to uncover the multilayered meanings of heritage locations. Drawing on Activity Theory, we examine the ecology of actors and tools necessary to facilitate the co-curating and experiencing of sites of cultural heritage.