Geometry is a basic discipline in STEM education. Recent educational reports, however, suggest that geometry is one of the subjects that sees the lowest levels of performance in the math curriculum. This paper presents a gamified itinerary through digital activities designed to teach geometry. Our aim is to attract Primary School children into the world of geometry. First, we scaffold geometry outcomes to take students progressively from basic geometric shapes to a stronger understanding of complex three-dimensional (3D) properties. Second, we use gamification to introduce fun into the learning process. Third, we propose digital activities in virtual environments, with which students can, in particular, develop 3D spatial perception. Concretely, children are immersed in a two-dimensional (2D)–3D world in which they play the role of architects who manipulate 2D and 3D shapes to create buildings. Results obtained in the evaluation of the system with 60 children showed an improvement in both their learning and their interest in math. Both children and teachers rated the experience very positively.