In the new millennium, given the continued expansion of technology, materials science and telecommunication coupled with development of social and geo political systems, we can expect the design and shape of our urban environment to change enormously. This publication, the result of the Council on Tall Buildings and Urban Habitat 6th World Congress Cities in the Third Millennium, examines the issues which should be addressed if we are to have a common understanding of the forces of change. Experts in architecture, engineering and planning contribute a commentary on the existing condition of...