5. Yellowstone National Park • Wyoming A mere $30 buys you and your family a 7-day pass to Yellowstone—compare that to a theme park! Humans have been visiting the Yellowstone area for over 11,000 years but the National Park wasn’t established until 1872 and it’s still a hugely popular destination. No summer is complete without spending a few nights under the stars and there’s plenty of camping areas if you want the full-on outdoorsy experience. Of course there are less rustic options if you can’t live without amenities like indoor plumbing and beds with mattresses. Then you can spend your days hiking, exploring the sites and taking in stunning natural wonders like Old Faithful, located in Yellowstone’s Upper Geyser Basin—home to 60% of the world’s geysers.