http://agathe.gr/overview/the_archaeological_site.html
The Athenian Agora The Agora of Athens was the center of the ancient city: a large, open square where the citizens could assemble for a wide variety of purposes. On any given day the space might be used ... In the spheres of education and philosophy, however, Athens maintained her preeminence. The Academy, founded by Plato, and the Lyceum, founded by Aristotle, continued to flourish.