In the U.S., we’re fortunate to have some incredible national treasures, our national parks. And to entice visitors throughout the year, the National Park Service offers fee-free dates – the next one is Monday, Aug. 25, the organization’s birthday! (Oh, and mine, too! No wonder I’m such a “green” tree-hugger and park lover!).

The National Park Service also wants you to know that only 133 of The U.S.’ 401 national parks ever charge an entrance fee. Amazing! And for those that do, a true bargain is the $80 annual pass that gets you in to all national parks, national wildlife refuges, national forests and much more – more than 2,000 sites in all.

Additional free entrance days in 2014 are National Public Lands Day on Sept. 27, and Veterans Day on Nov. 11.

Over the past few years, my friends and I have gone hiking in some of the most breathtaking parks. Here are some of my favorite photos (that I could quickly grab!):

What are you waiting for – get out and see all of the majestic beauty the U.S. has to offer! And happy birthday, National Park Service!

Which is your favorite National Park?

This post was originally published August 23, 2013, and was updated August 22, 2014.