What landmarks of greek (hellenic) culture would you consider the most significant as examples of "classicism? "?

Classicism is the term used to define the following of Ancient Greek and Roman culture and art, especially around the Age of Enlightenment. However, this genre has its origins much earlier in European history. The states of the Hellenistic period of Greek history (323-31 BC) were very careful in preserving their culture’s past, and much of what we know about Ancient Greeks is due to the work of Hellenistic Greeks.  

An example of this movement was the Library of Alexandria. Many Hellenistic scholars studied in Alexandria and contributed to the conservation of ancient texts.

The spread of gymnasia and theatres was another way in which classical Greek culture was preserved and spread. Higher education schools became more popular as well.