Conception and design of a “new town” with target population of 270,000 in a 1,140 hectares area in the municipality of Sao Joao da Barra, Rio de Janeiro State. This city is being designed to give support for the Port, Logistics and Industrial Complex of the Açu Port. The main structure of “Cidade X” derives from the pre-existing environmental and physical conditions of the area, which resulted in a network of lakes and canals that create a safe occupation level for the implementation of the project, solve the drainage issues, provide quality public spaces and cityscapes, and enables water transport. Guidelines for urban end environmental sustainability permeate the whole of the project that also contemplates issues of mobility and accessibility, density, mix of uses, compact neighborhoods, jobs generation, pedestrian circuits, alternative public transport and strategic projects to enhance identity.