The content of this Special Issue has its origin at the “5th International FIG Workshop on 3DCadastres”, organized in Athens, Greece, 18–20 October 2016. The Workshop provided a further stepping stone to identifying key issues and challenges within 3D Cadastres developments, as well as exchanging ideas and solutions between scientists from academia, industry, and government. After the workshop, authors of selected papers (or in some cases, two teams of authors of related papers) were invited to publish in this Special Issue, which is devoted to the legal, organizational, and technical aspects of 3D Cadastres. Therefore, this Special Issue is where practice and research meet, influence, stimulate, and support each other, showing the progress in the key areas of 3D Cadastres, including the legal framework of 3D Cadastres, initial registration of 3D parcels, 3D data management, visualization, distribution, and delivery of 3D parcels. The 13 papers published in this Special Issue are the end result of the authors’ hard work and a rigorous journal’s peer review process. We would like to thank the authors for their valuable contributions and of course express thanks to the IJGI Editorial Office and the reviewers for their thoughtful suggestions and constructive criticism. Even though all papers in this Special Issue stand on their own, depending on cultural, geographical, and technical differences, we have tried to produce a rather holistic approach, covering this field of research. Moreover, we have highlighted similarities and dissimilarities in addressing important 3D Cadastral topics, as follows.

This publication is the result from the International Federation of Surveyors (FIG) joint commission 3 ‘Spatial Information Management’ and commission 7 ‘Cadastre and Land Management’ Working Group on 3D Cadastres. The increasing complexity of infrastructures and densely built-up areas requires a proper registration of the legal status (private and public), which only can be provided to a limited extent by the existing 2D cadastral registrations. Within the FIG Working Group the concept of 3D Cadastres with 3D parcels is intended in the broadest possible sense: 3D parcels include land and water spaces, both above and below surface. The level of sophistication of a 3D Cadastre in a specific country will in the end be based on the user needs, land market requirements, legal framework, and technical possibilities. This FIG publication collects the best known practices related to 3D Cadastres in a single book organized in five coherent chapters: Chapter 1. Legal foundations Chapter 2. Initial Registration of 3D Parcels Chapter 3. 3D Cadastral Information Modelling Chapter 4. 3D Spatial DBMS for 3D Cadastres Chapter 5. Visualization and New Opportunities The FIG publication ‘3D Cadastres Best Practices’ provides a clear and comprehensive overview to both the newcomers and experts in the 3D Cadastres community.