SAFAR is a mobile Augmented Reality application that makes possible to see in real-time the ‘Sagrada Familia’ as it will look like when it be finished. The application successfully integrates outdoor tracking and 3D rendering processes to provide an augmented view of this under construction monument to city travellers, equipped with Nokia mobile phones. This outdoor tracking process includes a custom skyline detection algorithm, which provides real-time tracking and avoids not only external calibrations, but also additional sensors connected to the mobile phone. Moreover, the occlusion problem of the resulting images are improved by means of predefined drawings sequences, which control the combination between computer-generated and displayed video images. The performance evaluation results show that both the outdoor tracking and the 3D rendering techniques combined in SAFAR requires relatively low computational load, while providing a proper accuracy.