The buildings were better in the Hellenistic Civilization than Greece because of the spread in cultural customs
Legacy of Alexander the Great
Alexander the Great married a Persian woman and spread greek culture.
Math and Science
In maths, they created the Pythagorean Theorem which is still used today. In Science, they used basic physics to create inventions. They also came to the conclusion that the Earth is round, accurately calculate its circumference, and that the earth orbits the sun.
There was a 'slogan' created that doctors today still use, "Help the sick according to my ability and judgment but never with a view to injury and wrong". They looked for many cures to treat illnesses, too.
There were many customs that were traded because of Alexander the Great and his expedition. He also influenced people to create the Hellenistic Civilization.
Women were able to learn to read and write. They were also morally equal to men and able to get jobs and stuff that men could do.