Early Greek temples were similar to those of nearby cultures. That is to say they were simple 4 walled structures that housed the statue of a deity. As time progressed the Greeks innovated on this basic design by adding rows of columns on all sides, that screened, but did not entirely hide the inner structure. 

The Parthenon is a beautiful example of a rather severe style: the Doric order. The Doric order was one of the earliest Greek orders, but continued to be used on the Greek mainland even after other orders had been created. It was much less common in cultures that imitated Greek art, such as the Romans and Renaissance Europe.

There is a long-standing myth that the Romans invented the arch. This is simply not true, arches can in fact be found among ancient Greek ruins. They were mostly used underground. While the Romans didn’t invent the arch, they were the first to put it to wide use.

While many early civilizations sought to show the importance of a building by its size, the Greeks aimed, not so much for immense structures, but properly proportioned ones. We are still using their standards of proportion on art and architecture today. This doesn’t mean that there were no large Greek temples, but this was not a common characteristic.

Some Greek temples are in fact massive, but for the Greeks religion and art were centered on man. The people who used the temples were in some ways the focal point, not the afterlife, or strange and exotic deities. Because of this the temples were supposed to be more in proportion to the people who used them.

Ionic and Corinthian architecture was marked by taller, slenderer columns. Even the Doric temples, still built on the Greek mainland were less squat that their predecessors. The Greeks felt that this gave the buildings a lighter and more delicate feel.

The Column of Trajan tells the story of Trajan's victory against the Dacians.  Over 128 feet high, the narrative wraps around the entirety of the column and tells the story over 625 feet of marble.  As a result, the compositions are crowded and the entire story is difficult to view in its entirety.

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The defeated Dacians are depicted on the base of the column. They are shown as being worthy opponents to further highlight how significant the victory was for Trajan -- they appear strong, which shows how strong Trajan's army needed to be to defeat them. Above the defeated Dacians is a victory laurel to again highlight the significance of winning the battle against them.

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Originally, two libraries stood next to the column. Each had manuscripts detailing the Roman-Dacian war. One had the manuscripts in Roman, and the other in Greek. (Lamassu guardians are associated with Assyrian architecture and art, and steles, such as the Stele of Hammurabi, are associated with the Babylonians.)

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Ancient Greek and Roman architecture can be broken down into three main chronological groupings, from oldest to youngest: the Doric, the Ionic, and the Corinthian. As a building of the Roman Empire, the Pantheon, built between 27 BCE and 126 CE, is emblematic of the Corinthian order, especially its ornate columns lining its portico.