The study presents the development and testing of a model for explaining the learning outcomes when individuals use 3D virtual environments (VEs) in informal learning settings. For that matter, a VE was developed, presenting the work of a sculptress, namely Nausica Pastra. The following subjective factors were considered so as to build a research model: perceived usefulness, perceived ease of use, motivation, presence, perceived application's realism, as well as the enjoyment when using VEs. Self-reported data together with the results of tests embedded in the VE were gathered from 612 individuals. Structural Equation Modelling was employed for model testing and parameter estimation. The analyses of the results revealed a good model fit and 53% of the variance in the learning outcomes was explained. Out of the twenty research hypotheses, fifteen were supported. It was found that the most significant factors affecting the learning outcomes were motivation, perceived ease of use, perceived usefulness, and enjoyment. The implications of the findings for experts involved in the development of virtual museums are also discussed.