Tunnel

"We recently began traveling through the tunnels to avoid the guards, but many of the entrances in the city are broken. By using them, we can get to our destination rapidly, without encountering resistance."

- Niccolò Machiavelli about the tunnels.

Tunnels were a means of travel in Rome, and were the equivalent to the Fast Travel Booths. Ezio was first introduced to the tunnels by Niccolò Machiavelli, wherein he stated that the tunnels were used to arrive at destinations rapidly, while avoiding guards. There were a total of nineteen tunnel entrances throughout Rome.

Renovations
Initially, there was only one available tunnel entrance, leaving the other eighteen to be renovated by architects. The three tunnels that were located outside of the Rosa in Fiore, Barracks, and the La Volpe Addormentata would be automatically renovated once the respective building fronting it was; making them the only ones that were required to be restored.

Each district could be accessed via tunnel with the exception of the Vaticano District. Every standard entrance to the tunnels look alike, and had the letters SPQR (Senatus Populusque Romanus) engraved over their gates.

Tunnel Locations

 * Centro District
 * Tiber Island Hideout
 * Piazza del Popolo
 * Augustus Mausoleum
 * Pantheon
 * Campidoglio
 * Rosa in Fiore
 * Porte Tevere


 * Campagna District
 * Barracks
 * Northern Campagna
 * Southern Campagna
 * Castra Praetoria
 * Terme di Diocleziano
 * Colle Viminale


 * Antico District
 * Colosseum
 * Porta Nomentana
 * Palazzo Laterano
 * Terme di Caracalla
 * Thieves Guild
 * Roman Forum

Trivia

 * In the novelization of Brotherhood, Machiavelli says that Giovanni Auditore discovered the tunnels.
 * When Ezio makes use of the tunnels, there is a brief cutscene of him opening the latch on the gate and entering, though the player is not able to see or travel through the tunnels themselves.
 * Ezio can make use of a special tunnel to pass directly from the Tiber River into the Tiber Island headquarters.
 * Tunnel entrances will glow white while using Eagle Vision.
 * Ezio hides the Apple of Eden inside a tunnel under the Colosseum.
 * When you go in a tunnel during a mission or assassination contract, all progress in it will be lost.

Source

 * Assassin's Creed: Brotherhood