Flamingo Park

The park is open all year with no one to man the entrance after hours.
There is not an actual gate whatsoever, so you can drive right in.
The campground is at the end of the road (appx 36 miles) from the everglades national park entrance.
It is called Flamingo.

That is an Osprey in the tree, and the other birds are the Brown Pelican (a bold one)
and the Great Blue Heron along side the manmade canal.