You don't really appreciate the scale of the thing until you climb the steps to the top. You get great views of the city and a feel for slightly more modern history - there's a list of the places where the modern Olympic Games have been held since its start date in Athens, including the two that were cancelled due to the second world war.
Did you know . . . at the 1948 Olympics athletes were asked to bring their own food because there was still rationing in the UK. (sorry, I couldn't help myself)