When Ken Burns describes Yellowstone National Park, his sense of wonder is palpable.
"When you're there, you feel like you're at the moment of creation," Burns says.
The award-winning filmmaker would know. As co-creator of the PBS series America's Best Idea: The National Parks, Burns and his team spent months filming in national parks across the United States.
YOUR GUIDE TO YELLOWSTONE: What to do, where to stay and more
Burns sat down with USA TODAY and shared the secrets of Yellowstone and nine other national parks for a special 10-part series, "Secrets of the National Parks."
"Yellowstone is the world's first national park. Eight years after Yosemite was set aside, [the U.S.] decided to set aside this beautiful, attractive land ..." Burns explained. "But at that time in 1872, when President Ulysses S. Grant set it aside, there was no state to give it to and so it fell to the national government to take care of it. So it became the world's first National Park."
Don't visit Yellowstone and expect to conquer it all in a day's hike. Burns says the park has "so many different features that you could spend days there and realize that you still hadn't touched it."
YOUR TAKE: Submit your best national parks photos
The true secret to Yellowstone? Go at a particular time of year. Check out the video above to hear Ken Burns describe the best time to visit Yellowstone National Park.
Check back with USA TODAY Travel weekly for new installments of "Secrets of the National Parks," featuring Ken Burns' insights into Yosemite, Grand Canyon, Arches and more.