This paper explores the potential learning benefits of 3D Learning Environments (3DLEs). It presents definitions of key terms and analyses the learner-computer interactions facilitated by 3DLEs, in order to identifj! the unique characteristics of such environments It is argued that the most important potential contribution of 3DLEs to conceptual understanding is through facilitation of spatial knowledge development. The effectiveness of3DLEsfor spatial learning is discussed, drml'ing on7iterature from a range ofdisciplines. Aspects ofa research agenda are identified including exploration of the characteristics of 3DLEs that are most important for spatial learning along with issues in designing appropriate lem71ing tasks.