Biscayne National Park sits just east of Homestead, and most people driving down to the Everglades have no idea it's there. That's a shame. Ninety-five percent of the park is water, and the Dante Fascell Visitor Center is your starting point for all of it. Parking is free. Admission is free. The only thing that costs you is time, and it's worth every minute.
The visitor center itself is genuinely interesting. The building has an old-Florida character that feels nothing like a modern park facility, and the exhibits inside cover the park's history, ecology, and the people who lived here long before it became protected land. Rangers are responsive and helpful, which matters when you're trying to plan a day on the water.
From here you can book guided kayak and snorkel tours, or launch your own kayak or canoe from the ramp on-site. The Jones Lagoon paddle is a popular route through mangrove tunnels and open bay. (Bring bug spray. Seriously. Don't test this one.)
There's also a boardwalk that runs along the waterfront, easy walking, good for fishing, and a nice way to ease into the morning before a tour. Families do well here: the half-mile walk is manageable for kids, rangers are great with scout groups and school trips, and the whole place has a calm, unhurried feel.
If you're spending a few days near the Everglades, Biscayne deserves a spot on the itinerary. Two national parks, one trip. Not a bad deal.