The document provides background information on ancient Roman architecture and describes several important sites in Rome. It discusses how the Romans adapted architectural styles from the Greeks and Etruscans and were able to construct large buildings using arches, domes and concrete. It then outlines some of the key structures in Rome, including the Servian and Aurelian city walls, the Appian Way, the Pantheon, Roman Forum, Baths of Caracalla, Circus Maximus and the Colosseum.