The drawing shows one of the last Michelangelo’s architectural project. This is one of the studies carried out to the realization of Porta Pia, monumental gate designed to close the homonymous street, wanted by Popo Pio IV Medici, that was supposed to merge the Quirinal with Saint Agnes. The gate, leaning against a high wall, is situated on two steps and shows pillars whose hold up a high trabeation that culminates in a triangular moulded tympanum. On the top is placed, just sketched, the drawing of the Papal arms.