I feel kind of dumb right now. For whatever reason, I thought Mammoth Cave was Kentucky's only national park. I guess I thought everything else was taken care of at the state level.

Well, anyway, I've put that minor bit of embarrassment behind me because I have much more important things to talk about, like free visits to America's national parks. That's right, the National Park Service has announced the entrance fee-free national park visit days for 2022.

So take note of Kentucky's national parks and plan accordingly. Outside of Mammoth Cave, where many of you are likely already planning getaways--there are seemingly bottomless pits of activities surrounding the world's largest cave system, don't forget to explore the Abraham Lincoln Birthplace in Hodgenville, on the other side of Elizabethtown. See, I've BEEN there and didn't realize it was a national park. But I digress. It's a fascinating look at the early life of our 16th president and features a comprehensive welcome center, the first Lincoln Memorial, Lincoln's symbolic birthplace cabin--it's a replica inside a large memorial facility at the top of a hill, and Sinking Spring, which is a well where the Lincoln and Karst families drew water. You have to walk down into it but it's very cool and, well, quite LITERALLY very cool; it stays the same temperature throughout the year.

There's also Big South Fork on the Kentucky-Tennessee line near the Cumberland River; Camp Nelson in Nicholasville; Cumberland Gap in Middlesboro; Fort Donelson, also on the Kentucky-Tennessee border; the Lewis & Clark National Historic Trail, sections of which can also be found in 15 other states; the Mill Springs Battlefield; and the Trail of Tears, sections of which can also be found in eight other states. Looks like you may have your work cut out for you.

There will be five free visit days this year, beginning Monday, January 17th, Martin Luther King Jr. Day. The other four will be April 16th, the first day of National Park Week; August 4th, commemorating the Great American Outdoors Act; September 24th, National Public Lands Day; and Veterans Day, November 11th.

I always say there's nothing like looking forward to something and making plans now to visit all these wonderful Kentucky parks certainly fits that bill.

LOOK: Stunning vintage photos capture the beauty of America's national parks

Today these parks are located throughout the country in 25 states and the U.S. Virgin Islands. The land encompassing them was either purchased or donated, though much of it had been inhabited by native people for thousands of years before the founding of the United States. These areas are protected and revered as educational resources about the natural world, and as spaces for exploration.

Keep scrolling for 50 vintage photos that show the beauty of America's national parks.

RANKED: Here are the most popular national parks

To determine the most popular national parks in the United States, Stacker compiled data from the National Park Service on the number of recreational visits each site had in 2020. Keep reading to discover the 50 most popular national parks in the United States, in reverse order from #50 to #1. And be sure to check with individuals parks before you visit to find out about ongoing, pandemic-related safety precautions at www.nps.gov/coronavirus.

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