Three-dimensional content is a novel modality used in numerous domains like navigation, post production & cinematography, architectural modeling and urban planning. These domains have benefited from the enormous progress has been made on 3D reconstruction from images. Such a problem consists of building geometric models of the observed environment. State of the art methods can deliver excellent results in a small scale but suffer from being local and cannot be considered in a large scale reconstruction process since the assumption of recovering images from multiple views for an important number of buildings is rather unrealistic.  On the other hand several efforts have been made in the graphics community towards content creation with city engines. Such models are purely graphics-based and given a set of rules (grammars) as well as dictionary of architectures (buildings) can produce virtual cities. Such engines could become far more realistic through the use of actual city models as well as knowledge of building architectures. Developing 3D models/rules/grammars that are image-based and coupling these models with actual observations is the greatest challenge of urban modeling. Solving the large-scale geometric modeling problem from minimal content could create novel means of world representation as well as novel markets and applications. In this talk, we will present some preliminary results on large scale modeling and reconstruction through architectural grammars.