Porta Settimiana is one of the gates of the Aurelian walls. It rises at the northern vertex of the rough triangle traced by the town walls - built by Emperor Aurelian in the 3rd century - in the area of Trastevere an up through the Janiculum. The gate marks the beginning of Via della Lungara and is the only gate, on the right bank of the Tiber (the other ones are Porta Portuensis, no more existing, and Porta San Pancrazio), that rises just in the place where it was built, despite its restorations and rebuildings. There are several theories about the meaning of the name. An etymology related to its location north of the Temple of Janus looks plausible.