CODECITY is a language-independent interactive 3D visualization tool for the analysis of large software systems. Using a city metaphor, it depicts classes as buildings and packages as districts of a "software city". By offering consistent locality and solid orientation points we keep the viewer oriented during the exploration of a city. We applied our tool on several large-scale industrial systems. Categories and Subject Descriptors D.2.7 [Distribution, Maintenance and Enhancement]: Restructuring, Reengineering General Terms Languages, Design, Human Factors