The Catacombs of Rome (Italian: Catacombe di Roma), were one of the Lairs of Romulus. They were located underneath the city of Rome, and were constructed in the 2nd century. As Christianity was illegal at the time, the catacombs were built to serve as more space to secretly bury their dead. The entrance to the catacombs was located right next to the Pyramid of Cestius.
The catacombs were made up of several winding, maze-like tunnels, and the entrance to the Shrine of Romulus was cut into the wall of a seemingly bottomless pit, requiring Ezio to drop down and grasp the wall to enter it. Near the end of the catacombs, Ezio was attacked by several Followers of Romulus, but they were easily dispatched. Upon reaching the shrine, Ezio took the key and scroll of Romulus within it.
- This particular Lair of Romulus must be completed within 8 minutes to achieve full synchronization.
- Should Ezio ever come to a fork in their lair, scanning the wall in Eagle Vision would reveal an arrow pointing in the right direction.
- Alternately, the flames of each torch on the wall were also blowing towards the path leading to the exit.
- If Ezio scanned the large cathedral near the entrance with Eagle Vision, two of the cryptic messages that Clay Kaczmarek left on the floors of Abstergo Industries' facility in Rome could be seen, albeit partly obscured by objects in the room. One was the word puzzle that decoded to: "Artefacts sent to the skies to control all nations to make us obey a hidden crusade; do not help them." The other was the pyramid of Eden with the Apple on top.
- There were several spots throughout the catacombs where Followers of Romulus could be seen running through them.