At the end of the Middle Ages, the gate was sealed by bricks. Instead, four new passages were created flanking the original one to accommodate increasing traffic. During his tenure, Pope Callixtus II bore a small channel through the sealed entrance for the Acqua Mariana, a river whose stagnant waters would be the cause of an outbreak of plague in 1601.
In Assassin's Creed: Brotherhood, all the gates of Rome are misidentified, though Shaun Hastings's database entries remain factually correct. The gate, located at the southwestern corner of Trastevere, marked as the Porta Metronia is actually the Porta Portuensis while the proper Porta Metronia is mistakenly labeled as the Porta Tiburtina. For the sake of convenience, this article assumes that Shaun Hastings's research is correct whereas the Animus 2.01 labeled the gates erroneously.