Roman architecture

The Romans widely employed, and further developed, the arch, vault and dome (see the Roman Architectural Revolution), all of which were little used before, particularly in Europe.^[3] Their innovative use of Roman concrete facilitated the building of the many public buildings of often unprecedented size throughout the empire. These include Roman temples, Roman baths, Roman bridges, Roman aqueducts, Roman harbours, triumphal arches, Roman amphitheatres, Roman circuses palaces, mausolea and in the late empire also churches.

The monumental Colosseum, a Roman amphitheatre from the 1st century AD

Roman domes permitted construction of vaulted ceilings and enabled huge covered public spaces such as the public baths like Baths of Diocletian or the monumental Pantheon in the city of Rome.
Art historians such as Gottfried Richter in the 20's identified the Roman architectural innovation as being the Triumphal Arch and it is poignant to see how this symbol of power on earth was transformed and utilised within the Christian basilicas when the Roman Empire of the West was on its last legs: The arch was set before the altar to symbolize the triumph of Christ and the after life. It is in their impressive aqueducts that we see the arch triumphant, especially in the many surviving examples, such as the Pont du Gard, the aqueduct at Segovia and the remains of the Aqueducts of Rome itself. Their survival is testimony to the durability of their materials and design.