The National Park Service is throwing itself a 100th birthday party and this month everyone is invited.

Southern Campgrounds Great Smoky Mountains National Park, TN
Straddling the border of North Carolina and Tennessee, the Great Smoky Mountains National Park is America's most-visited and one of the most biologically diverse forests in the country. With historic log buildings, plenty of waterfalls, and a heavy dose of refreshing Appalachian Mountain culture, this park has plenty of stunning places to camp. Some close at the end of October, but others (like Cades Cove and Smokemont) are open year-round.For more information, see the official website.
| Credit: AndrewSoundarajan

To mark the double occasion of their centennial and National Park Week, for two weekends this month, every National Park from sea to shining sea, will be throwing open their doors and doing away with admission fees.

From April 15-16 and 22-23 beloved Southern outdoor spots like the Great Smoky Mountain National Park, the Blue Ridge Parkway, Hot Springs Reservation, and Everglades National Park will be absolutely free. It's a great excuse to finally go horseback riding on the 450-mile Natchez Trace trail in Tupelo, put on your spelunking hat to explore Kentucky's Mammoth Cave, float down the river in Texas's Big Bend National Park, or take a weekend trip to the shore at Cape Lookout in North Carolina.

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If you can't make it to the park of your dreams (we're looking at you Dry Tortugas National Park) in April, there are a few other weekends when the parks waive their entrance fees. Save a few dollars when you explore the parks on August 25 (the National Park Service Birthday), September 30 (National Public Lands Day) and on the weekend of Veterans Day. And, if you're lucky enough to be friendly with a fourth grader, don't forget they are entitled to free entry all year round and parents (and grandparents) can come along for the fun, too.