To understand a writer's work, often it's important to understand something about where he or she lived and worked. To help you deepen your understanding of Plato in this regard, here's the homepage for a website dealing with ancient Athens.
If you'd like to zero in on one aspect of Athens and visualize it, here are some pictures and drawings of the Acropolis and the Theater of Dionysus.
Interested in putting the writings of Plato into a political context? This is the Columbia Encyclopedia entry for the Thirty Tyrants. Click on the embedded links found there. How does Plato figure in them?
Here is a reproduction of The School of Athens by Raphael, as well as some info about the painting. Where are Plato and Aristotle found in the painting? What do you make of their placement?