The Basilica class security bureau is an advanced structure added to more developed Romulan colonies. The purpose of which is to supervise and train security personnel.
They are known to be somewhat despised by citizens of the Romulan Star Empire but they would not say this openly. This is because that, while the security officers are tasked with protecting the citizens from outside threats, they are also tasked with making sure that no sedition occurs within the colony. Its large structural frame gives it an excellent view of the colony site for this role. This also serves as a reminder to the people of their governments eternal vigilance.
The lower floors of the building house the armoury, , practice range, gymnasium, lecture hall, workstations and prison cells. While the upper floors are dedicated for the more elite security officers with a range of sensor equipment which are, supposedly, known to be able to record every word spoken within the colony. The huge sensor array emiiter on the upper levels are noted to enhance the performance of sensor grid.
There is a noted sightings of Tal Shiar marked computer equipment. Regardless, the introduction of these structures on to a Romulan colony has a noted effect of reducing colonial riots as well as insurrections by 86%. (TOS video game: New Worlds)