The most fun I've had at any National Park as a kid was at Zion. Sitting lazily in an inner tube on the water or going down the little rapids was the perfect way to spend the day. You can keep your hiking, I'll stick with laying in the water :)
May 10: National Train Day. From San Francisco cable cars to the New York City subway system, trains are an iconic form of transportation we often take for granted. Today celebrates the rich history, romanticism, and cultural importance of trains -- all aboard for fun!