The Pantheon, which was built and completed under Hadrian in A.D. 125, has an interior that was designed to be a perfect sphere. The height of the dome is the same as its diameter. In the center of the top of the dome is a hole called an oculus, which is the only window in the structure. The Pantheon is still the largest brick dome in existence. To be able to build the enormous dome without modern reinforcement, several architectural methods were used to lighten the dome. The thickness of the dome gradually thins towards the top, recessed panels were used in the interior of the dome to further thin the dome and the concrete was made of material that weighed less towards the top.
The Colosseum, completed under the reign of Domitian in A.D. 82, was and is an architectural marvel, especially for its time. Covering about 6 acres, the Colosseum is elliptical in shape and three stories tall. On the outer surface, each story has a different type of column. The inside of the Colosseum could be transformed from a large pool for mock sea battles to terrain for gladiator battles.
Trajan's Column, erected in A.D. 113 under Emperor Trajan, stands 138 feet tall and is covered in relief illustrations detailing Trajan's battles against Dacia (now Romania) in the early second century A.D. The statue atop the column was originally an eagle, but after Trajan's death the eagle was replaced with a statue of Trajan himself and later the statue of Trajan was replaced with one of St. Peter.
Built between the last century B.C. and the fourth century A.D., the Roman Forum was built in the valley between the Capitoline Hill and the Palatine Hill in Rome. The Roman Forum was the center of politics, commerce and law in Rome before the empire fell. After the fall of Rome, the Forum was forgotten and used during the Middle Ages as a pasture. Much of the architecture was raided for building materials for other structures.
Circus Maximus, first built in the sixth century B.C. under King Tarquinius Priscus, was the biggest stadium built in ancient Rome. At one time it could seat 250,000 people, which was about one-fourth of the population of Rome. The stadium setting was very like modern-day horse racing. Chariots drawn by horses raced against one another with stadium onlookers betting on one chariot. Eventually the stadium fell out of favor and was raided for building materials for other structures, and today about all that can be seen of the place is a large grassland.
