Constructed sometime between 848 and 1455, the Porta Turrionis was so named because it stood next to a tower (turrionis) built by Pope Nicholas V. In 1990, the location of the was enlarged to accommodate the traffic of cars moving through the entrance of the Vatican. Consequently, the original gate was shifted several meters to the side and permanently closed.
- In Assassin's Creed: Brotherhood, all of the gates of Rome are misidentified, though Shaun Hastings's database entries remain factually correct. The gate marked as Porta Turrionis in the game is at the far southeast corner of Rome in the Antico District—nowhere near the Vatican City—and a part of the Aurelian Walls; this gate is in actuality the Porta Asinaria. This error is in spite of the fact that the database entry on Porta Turrionis accurately describes it as a gate of the Leonine Walls in the Vatican, not the Aurelian Walls. For convenience, this article assumes that Shaun Hastings's research is canonically correct while the Animus 2.01 labeled the gates erroneously.