Roman architecture consisted of numerous structures, styles and utilitarian solutions that are still used in modern times. For example, the Romans popularized the use of the dome and the arch. Their use of aqueducts and sewage systems revolutionized the science of civil engineering.
One of the most notable influences of Roman architecture on modern constructions is the use of columns. American courthouses often feature a column design that evokes the buildings of Rome. Arches are also a major Roman contribution to western architecture. Although the Romans did not come up with the arch (the structure dates all the way back to Mesopotamia in the second millennium B.C.), they made widespread use of it in an unprecedented way. Whereas previous cultures had only sporadically used the arch for underground drains, the Romans applied it to gates, bridges and aqueducts. Roman aqueduct systems were the most ambitious projects of their kind in the ancient world and have greatly influenced modern public water systems.
The Roman sanitation system was innovative as well. Running water flowed through latrines (an early precursor to the toilet) and carried waste through a complex network of drains to a nearby stream. Although the knowledge of this sewer system was lost during the Dark Ages, engineers and architects of the modern era developed public waste disposal methods very similar to what the Romans used. Modern architecture is also indebted to ancient Rome for pioneering the use of concrete.