Conventional approaches to a virtual heritage site that provide interpretations through curated content allow visitors only the lowest level of engagement, which is paying conscious, intentional attention to the content. In this paper, we propose a trajectory for visitor experience to a virtual heritage site that facilitates a higher level of engagement by letting visitors make their own interpretations. We developed a mobile virtual reality (VR) application that delivers this trajectory, which allows visitors to author mixed reality (MR) content that represents personal interpretations. The application provides three types of virtual assets to compose MR content: historical assets, emotional assets, and personal assets. We describe how visitors generally followed our trajectory and used virtual assets, engaging with virtual heritage and making interpretations. We related our findings to a discussion of how to support personal engagement and rich interpretation in a virtual heritage site.