This paper addresses the problem of automatically align- ing historical architectural paintings with 3D models obtained using multi-view stereo technology from modern photographs. This is a challenging task because of the variations in appearance, geometry, color and texture due to environmental changes over time, the non-photorealistic nature of architectural paintings, and differences in the view- points used by the painters and photographers. Our contribution is two-fold: (i) we combine the gist descriptor [23] with the view-synthesis/retrieval of Irschara et al. [14] to obtain a coarse alignment of the painting to the 3D model by view-sensitive retrieval; (ii) we develop an ICP-like viewpoint refinement procedure, where 3D surface orientation discontinuities (folds and creases) and view-dependent occlusion boundaries are rendered from the automatically obtained and noisy 3D model in a view-dependent manner and matched to contours extracted from the paintings. We demonstrate the alignment of XIXth Century architectural watercolors of the Casa di Championnet in Pompeii with a 3D model constructed from modern photographs using the PMVS public-domain multi-view stereo software.