1. Roman Architecture
The Romans took the architectural traditions of the Greeks and their neighbors, the Etruscans, added some new innovations, and developed a architectural style of their own. Their great innovation in terms of materials was the invention of concrete.

2. The Arch vs. Post and Lintel Construction

3. The Aqueduct

4. The Coliseum
The upper two levels of arches would’ve held sculptures depicting gods and heroes.
The columns go from Doric, to Ionic and Corinthian the higher up you go.

5. The Interior Today

6. Could hold 50,000 spectators
There were 80 entrances, so people could enter and exit quickly through passages called vomitoria. The crowd could exit the building in mere minutes.
Entertainment included gladiatorial battles, hunts of thousands of exotic animals from Africa and the Middle East, and even re-enactments of historic naval battles at least once, when the interior was flooded.
Some of the entertainments were used to execute prisoners of war and criminals

7. The Dome

8. The Pantheon