Complex information systems are very difficult to represent and users often have problems to find relevant information; this is the case with Web navigation: users feel “lost”. Data contained in such systems can often be organized hierarchically, thus it is possible to represent it as a tree. However, most visualizations are cluttered because of the amount of information to display. We propose to solve these problems by using Virtual Reality (VR) techniques. After reviewing different 3D visualization methods, we decided to use cone trees. Unfortunately, the enhancement provided by graphic methods is not sufficient when hierarchies are very large; in such cases, trees must be pruned with filtering methods. We chose to structure and manipulate data with the eXtensible Markup Language [19]. XML allows the description and organization of any type of information. In this paper, we show how we implemented these principles in the field of network management (for networks based on Synchronous Digital Hierarchy (SDH) equipment). The application we developed eases navigation in data extracted from the Management Information Base (MIB) and accelerates access to useful information. In the future, we will apply these results to Web navigation.