Full disclosure: Shana Corey is a college friend of mine, but that's not what makes this book awesome. The illustrations are incredible and very unique. The story (which is true!) about an inventor who creates a pneumatic tunnel for a passenger train to help alleviate New York's traffic problems -- 40 years before the modern subway system was built -- is both interesting and entertaining. There's a kind of fun, steampunk feel to this book that I loved, and my sons (3 and 5) loved "The Secret Subway" because they love trains and inventions.