Today official is the 100th birthday of the National Parks Service! To celebrate everyone is allowed to visit any National Park for free from today Aug 25th till Sunday Aug 28th, so start planning your trip by visiting their website here:
National Park Service Centennial
They also have a fun website where you can photoshop a selfie of you in a national park here:
Some of my favorites are: Sleeping Bear Dunes Nat'l Lakeshore, Mammoth Cave Nat'l Park, Perry's Victory/International Peace memorial at Put-in-bay, and Pictured Rocks Nat'l Lakeshore.
What's Your Favorite?