The U.S. National Parks are invaluable treasures. One of my main heroes, John Muir, was instrumental in the creation of the first national park, Yosemite, where I took the above picture of El Capitan. Some of the parks you recognize right away: Yellowstone, Yosemite, the Grand Canyon, while others are less well-known. The national park system includes national heritage sites, national seashores, and national monuments, like my personal favorite Muir Woods.
It's pretty likely there's one near you unless you live in Delaware, which is the only state without a national park. So that means it's time to get out and visit one! Entry fees vary, but there are some days during the year that are free. This upcoming weekend happens to be one of those times: from Jan. 15-17, in honor of Martin Luther King, Jr. Day, the national parks are free. Click here to see the other dates for the year.