Between The Colosseum and the Piazza Venezia lies the Forum Romanum or Roman Forum. This area of ruins was once the center of the Roman Empire. The area was the vital heart of the city as well, where commerce, government and religion all came together. Before you enter the Forum, look for a vendor selling a guide book that shows how the ruins once looked. Many have clear overlays that you can flip down over a picture of the current ruin that will let you see how the forum was once laid out. As you walk among the grounds, you're sharing the same space as the emperors of the golden era of the Roman Empire. The temples of Vesta, Janus and Saturn are all here. The Arch of Septimius Severus was built to honor the emperor credited with extending the empire into the region of Mesopotamia. The numerous basilicas were not originally used as churches, but as business exchanges. A tour guide can point out the site where Julius Caesar was supposedly betrayed and murdered by Brutus. If you climb the stairs near the Arch of Titus, you can reach the Palatine Hill, one of the seven hills of Rome. The Farnese gardens, Livia's villa and the Iron Age village, dating to the 8th century B.C. where Remus and Romulus supposedly lived are all open to the public.