Travel can be a stressful experience and it is an activity that is difficult to prepare for in advance. Although maps, routes and landmarks can be memorised, travellers do not get much sense of the spatial layout of the destination and can easily get confused when they arrive. There is little doubt that virtual environments techniques can assist in such situations, by, for example, providing walkthroughs of virtual cityscapes to effect route learning. The London Travel Demonstrator supports travellers by providing an environment where they can explore London, utilise group collaboration facilities, rehearse particular journeys and access tourist information data. These services are built on the Distributed Interactive Virtual Environment (DIVE) software from SICS. In this paper we describe how the application was built, how it exploits the underlying collaboration services, and how the platform provides for scaleability both in terms of the large extent and detail of this application ...