"Shark Valley is a geological depression at the head of the Shark River Slough in far western Miami-Dade County and is currently part of Everglades National Park. Shark Valley empties into Shark River in the Ten Thousand Islands of Monroe County. Shark Valley characteristically includes sawgrass prairie that floods during the rainy season, hence the name "river of grass"—Pa-Hay-Okee, from the Mikasuki language—for such marshes in the Everglades. Shark Valley features a Visitor Center with educational displays, a park video, an underwater camera and informational brochures. The entrance to Shark Valley is located along Tamiami Trail (US 41) near the Miami-Dade–Collier County line."
40001 State Road 9336 Homestead, FL 33034
Website - Shark Valley
This is a very popular spot from my experience and closer to Miami than it is to Naples but well worth the drive as long as you know that personal experiences may vary. I have been here when there wasn't much more than gators to see as birds were sparse and times when the birds were plentiful. One notable feature is that the birds appear to be pretty accustomed to people allowing for excellent photos. While sitting near the bank of a canal I had a Little Blue Heron walk just a couple feel away and a Great Blue Heron wading a few feet farther away. Of course your results may vary but you'll certainly be able to get close to gators if that's your goal.