One of the best hikes in Everglades National Park is a slough slog into a cypress dome. Ranger Yvette Cano, the park's education director, explains what such a hike is like, and then she and Frank Dean, president and CEO of the Yosemite Conservancy, explain the challenges of funding educational and interpretive programs in the parks. They often are not part of a park's government-funded budget.

Chicken eggs are pretty good chum, but alligator and crocodile eggs, sea turtle eggs, and even bird eggs are also high on the menu for black-and-white Argentine tegus, a lizard that arrived in Florida through the pet store trade and is threatening to upend Everglades National Park's ecosystems.

There’s always something to learn when visiting any of the 423 units within the National Park System. How much do you know? Test your knowledge with this quiz and trivia piece and maybe learn a thing or two, as well.

EVERGLADES NATIONAL PARK _ It was an unlikely scene in a national park established to protect nature: bucket excavators, lumbering dump trucks, and bulldozers, heavy equipment more in place at sprawling construction sites, were rummaging through the muck not far from the park's Ernest F. Coe Visitor Center.