Roman architectural style originated from a combination of Greek and Etruscan but evolved into a style of its own. Among other innovations, Rome gave the world concrete, vaulting, roads, aqueducts and arches. The Sanctuary of Fortuna Primigenia (late 2nd Century BCE) utilizes axial planning like the Greeks but it also uses arches and a new material: concrete, to create this elaborate terraced structure. The arches allow for higher ceilings and more free space. It eliminates the need for columns by delivering the weight to the buttressed sides in a lateral thrust. By using concrete, material was less expensive and more readily available as opposed to transporting marble and other materials across the empire.
As the empire expanded, so too did its need for elaborate structures to exemplify and remind its people of its success. The Colosseum in Rome (ca 70-80 CE) is said to hold more than 50,000 spectators. The Colosseum is free standing and its weight is held up by the vaulting and arches. Three-quarter columns also support some weight on the first tier they were ionic, second Doric and third Corinthian. The structure had many entrances to allow for practical and efficient movement of the spectators. Its function was mostly to entertain with violent gladiatorial fights, bloody hunts against exotic animals imported from Africa and even re-enactments of naval battles. A large canopy could be pulled across the top in case of rain and for shading purposes to make spectating slightly more comfortable. To make the shows more elaborate and unpredictable the Colosseum had various trap doors and passageways underneath complete with training grounds for the gladiators.
Another Roman architectural wonder is the Pantheon (ca 118-125 CE). Revolutionary in its design and its exploitation of concrete and coffers, a huge dome and a design based off of the intersection of two circles creates the image of the interior as an orb of the earth and the dome as the heavens. Atop the dome is an oculus, with a diameter of 30 feet, this opening is the only source for light. To carry all the weight, basalt was added to the mix in the foundations and after modification the top stones were replaced with pumice to lighten the load. The thickness of the dome decreases as it nears the oculus and coffers functionally lighten the load while providing decoration.
It is believed that each coffer had a gilded-bronze rosette at its center so as to amplify the effect of the stars and the heavens. Without columns crowding the interior, and with only an oculus for the source of light, dramatic effects and symbolism are amplified as a result of the features of the Pantheon. New materials and innovations allowed for larger scale architecture that in turn expanded the purpose of each building by accommodating more people in the vast space.
