Greek and Romans
The Romans contributed the aqueduct which is an elevated water system. The present day example is a plumbing system. They also contributed concrete roads. They had 50,000 miles of paved roads used for trade and transporting roman military.
The Greek contributed 3 types of columns called Doric, Ionic, and Corinthian. These are commonly used in Washington D.C buildings. They also contributed theaters. They used theaters for comedy and tragedy. The theaters were built all over the ancient world. We now use them as theaters and opera houses.
Some of the Roman emperors were good and bad. Caesar Augustus was good because he issued new coins to promote trade and respected the senate. Nero, however was bad. He created the " Golden House" and blamed the Christians for the fire.
Some of the famous gods in Greek are Hercules, Zeus, Athena, and Hades. Hercules is known for strength and Zeus is known for the sky. Athena is the god of wisdom. Hades is the god of the underworld.