I would definitely suggest visiting Sarett, it has a wonderful nature center with live displays, snakes, turtles, a rabbit, and more, The Earth display with so many examples of rocks all neatly identified, a kids area to do fun nature-y things, and a gift shop with a large selection of books.
There are lots of trails, boardwalks, also the treetop trail and walkway which is a boardwalk that is 55 feet above the swamp forest floor, impressive. Here is what else we saw...
Grass of Parnassus
We found this plant and sat down to identify it. I thought the flowers looked like some sort of lettuce but the leaves didn't, hm... Marie discovered it to be a Smooth White Lettuce, Prenanthes racemosa, also known as Purple Rattlesnakeroot.
Close up of the Prenanthes racemosa flower. First we just saw one of these plants then we found many more.
Along the trail at Sarett Nature Center