Ideal Roman cities were designed around two central axes, which marked the area of the forum, forming an orthogonal urban grid. The Roman settlement of Barcino is a good example of this design.

The streets that today are designated Forum Street and Popilius Street (in the Roman era streets were not named) cross at right angles, forming the central axis of Lucentum.

In many cases, the streets of Roman cities were equipped with sidewalks, steps, and water supply and disposal (sewer) systems. Threshold Street was not endowed with sewers, but other streets, such as Forum and Popilius Streets, were (as shown in the photo).