For decades, television host and writer Rick Steves has shown viewers how to visit Europe. But the new edition of his book "Travel as a Political Act" has a loftier goal: changing the way they see the world. “If you travel thoughtfully, you find people who find different truths self-evident,” he says. “You have an opportunity to come home with the greatest souvenir, which is global perspective.” Istanbul, Turkey’s biggest city, straddles Europe and Asia, which makes it a fascinating place to visit, Steves says. “I consider Istanbul, along with Paris, London and Rome, one of the top four cities in Europe to see."