Curry Hammock State Park protects a stretch of Middle Keys coastline with beach, mangroves, seagrass flats, and paddling routes. It is one of the better low-key nature stops around Marathon, especially if you want time on the water without a full charter.
Kayaks are usually available to rent, and the park works for swimming, birdwatching, and a quiet picnic. It is not dramatic, but it shows the softer, wilder side of the Keys between the road bridges and resort strips.