Huffington Post     First Posted: 09/03/09 06:12 AM ET   Updated: 12/05/11 04:27 PM ET

While the same standard list may come to mind whenever you ponder the United States' National Parks, it is our hope here at HuffPost Green that this slideshow of our top ten best national parks you don't know about may just rearrange your mental checklist.

August 15th-16th marks the last in a series of three fee-free weekends to many United States National Parks. Here is the directory of national parks with waived admission.

Ready for a trip? Find a park near you or read up on the National Park Service's Family Fun activities.

To step your visit up a notch, why not participate in Geocaching, a global game in which participants hide geocache treasure, revealing its location via GPS device, and then geocachers search for the buried surprise. Get started here.

After voting on your favorite secret retreat, tell us what we've missed. What are you favorite National Parks?

Crater Lake National Park, OR
Oregon's Crater Lake National Park is praised as the gem of the Cascade Mountains. The Crater Lake caldera, or volcanic basin, was formed by the collapse of Mount Mazama nearly 8,000 years ago. After viewing the Park, visitors can hike, snowshoe, ski and bike along the Cascades mountainscape.
Rate This Photo
(Current Rank: loading...)
Possibly Worth A Visit
Better Go Pack!
1
2
3
4
5
6
7
8
9
10
Now Make Your Own Top 5
Average rating: loading... out of 10
Current Top 5 Slides
loading...
Users Who Voted on this Slide
loading...
loading...
HuffPost Community Top 5 Slides:
 

FOLLOW HUFFPOST GREEN