This paper presents research in progress on 3-D computer simulation and a virtual reality demonstration of a world heritage site that was destroyed in the earthquake (the citadel of Bam). In a comparative study with other examples of VR of cultural heritage, the approach of this research is introduced as analytic and comparative 3-D modelling (mostly as mesh or poly modelling) using diverse data resources such as 2-D maps, photos, etc. and VR demonstration of ten case studies as the result of first phase of the research.