"Its organizers described it as the most elaborate series of cultural events in Philadelphia history. It was, they asserted, 'an extraordinary coming together of the arts and culture of an entire city around an idea...' It took two years to put together. It lasted seven weeks. Eighty-one cultural institutions and organizations were involved, plus a number of Center City businesses."
Interesting thing about Mythos: it cost only $600,000 to produce (about $1 million in 2011 terms, adjusted for inflation) and was attended by a million people. PIFA's budget is $10 million.
Of course, as far as I can remember, Mythos didn't have its own ferris wheel.