It is one of the gates of the Real Cittadella, built around 1680 by Domenico Biundo and Antonio Amato. It was moved to the top of the steps of Piazza Casa Pia in 1961 because room was needed for the enlargement of the Cassaro shipyard, which was next to this historical military structure. The name of this wonderful Baroque gate comes from a preexisting church that was destroyed in order to make way for the Real Cittadella. The arch is decorated by three marble grotesque masks (the lateral ones supported the drawbridge), while the rest of the structure in made of limestone. The gate is framed by two large pillars, topped by rich capitals, garlands and wreaths. The box above the arch had an inscription, but the earthquake of 1894 destroyed it. At both sides, two large octagonal windows, magnificently decorated, frame the gate.