This paper presents a small part of a large project which consists of a psychological component with the evaluation of spatial skills of a population of children aged 7 to 10 years, a technological component, with the creation and development of a virtual city on computer and a didactic component, with the design and experimentation of a didactic engineering on spatial orientation with use of the virtual city (over 3 years with 5 classes). We first present the general context and the theoretical background of the project. Then, we present the virtual city developed in the project, and all the specificities linked to our didactic goals. Finally, we give a succinct overview of the three didactic engineering for Grades 2, 3 and 4, with all the adaptations of the technological environment involved to meet the evolutions over the three years.