In the helenistic period, the urban architecture is started to develop a form. Still the traces of Greek architecture are clearly visible, however this time the city planning is not developing organically but in an order of hierachy.
The cities now have main streets and avenues which are connected each other and separates the civic areas. The use of curvilinear elements slightly pass through the urban areas as architectural elements. The concept of city square is started to form. At the end of this era, a newborn empire slowly takes the lead in architectural inovations. The Romans; formed their architecture on the already existing foundations of the region. The arch element has became a esssential in buildings and constructs. The civic architecture and services proceeded a lot, after the fall of the emeperor Nero his palace is re utilized as a square. For instance an amphitheater is constructed on his palace’s pools. The use of monumental buildings such as temples have became constructed non religously but in a manner of paying respect to the status.
In addition to all of these, as it is mentioned before, the arch system has became essential elements of a building not just as a structural system but also as ornamentation. Because of the region’s local materials, constructs were built with a local reciepe of concrete so that the concept of interiority has born. The marble and stone elements usually used on facades and inner walls. As an example, the concept is clearly visible in the Pantheon. The building’s construction has started by a different architect and continued by another architect, so that we can see the classical era elements on the facade and the structural concept of dome and oculus inside.