Interior of St. Peters in Rome. The viewpoint of the perspective is raised, in order to enlarge the space. People appear very small. Eques Carolis Fontana┬┤s section drawing of St. Peter in Rome. More drawings of Sankt Peter to be found here: http://saintpetersbasilica.org/Plans/

Drawing of the cuppola with the scaffolding for painting the frescos. Michelangelos Plan of Sankt Peters