This paper examines children's and adults' attitudes to virtual representations of museum objects. Drawing on empirical research data gained from two web-based digital learning environments. The paper explores the characteristics of on-line learning activities that move children from a sense of wonder into meaningful engagement with objects and their original contexts both in their virtual space and their physical space. Considering the relationship between the virtual object and the physical object, and investigating how engagement with a virtual collection affects the attitude to the physical collection itself, the authors propose a model of the virtual museum learning experience, as a fourth dimension of museum objects. This model exhorts museums to go beyond merely creating virtual replicas of exhibitions, but instead to build multimedia rich immersive learning resources that foster meaningful and personal engagement with the target culture and thus genuinely extend intellectual access.