During the 1980s, ABACUS (Architecture and Building Aids Computer Unit, Strathclyde), in the Department of Architecture at the University of Strathclyde, researched issues surrounding the modelling and manipulation of large geometrical databases of urban topography. Initially, this interest lay solely in the ability to source, capture and store the relevant data. However, once constructed, these 3D data sets proved genuinely useful to a wide range of users. There ensued a demand from professionals for greater graphical functionality in the manipulation of these models and for the addition of contextual data. These demands often exposed deficiencies in the hardware and software systems then available. As a result, we focused development on research applications and deployment. The recent advent of the Virtual Reality Modelling Language (VRML) standards rekindled interest in this field, since VRML enables the addressing and solving of many of the issues that proved problematic in the past. The potential now exists to provide wide access to large-scale, multi-layered urban models.