Mangroves

Anne’s Beach is barely a beach in the conventional sense and that is exactly why it works with very small children. The water off Lower Matecumbe is so shallow that you can walk out several hundred feet and still be at knee height, warm as a bath in summer, with a soft bottom. A boardwalk runs behind it through the mangroves to a second stretch of sand. Parking is roadside and limited, there are restrooms but no concessions, and kiteboarders use the far end on windy days. It is free, which makes it the cheapest good hour in the Keys.

Cayo Aurora - universally called Gilligan’s Island - is a small mangrove key reached by a ferry that runs every hour or so from the Guánica shore. What makes it work with children is the geography: channels between the mangroves are shallow, clear, protected and warm, so they function as a set of natural pools with fish and starfish in them. There are picnic tables, boardwalks and restrooms and nothing else, so bring food and water. It closes on Mondays. Weekends bring a lively Puerto Rican family crowd with music and coolers, which is either the appeal or the reason to come midweek.

Laguna Grande is one of three bioluminescent bays in Puerto Rico and the one most families choose, because it is reached by a mangrove channel rather than open water and the tour operators run tandem kayaks with guides throughout. The dinoflagellates in the lagoon flash when disturbed, so your paddle blade, your hand in the water, and fish moving under the boat all glow. It genuinely works - but it depends on darkness, so tours only run around the new moon and are cancelled by a bright moon or heavy rain. The mangrove channel is narrow and requires steering, which is why the practical minimum age is around six.

Long Key’s canoe trail winds through a shallow tidal lagoon where the mangrove tunnels are close enough to touch on both sides and the water is often under two feet deep. It is a quiet, sheltered paddle with herons and small sharks in the shallows, and the reason to come. Bring your own boat: there are no rentals here and the dockage was removed. Be realistic about the rest of the park before you plan a day around it. Hurricane Irma in 2017 and Ian in 2022 took the oceanfront campground and the beach with it, and there are no plans to rebuild - only a few walk-up primitive sites remain, and as of mid-2026 those and the Golden Orb Trail are closed for construction. What is open is the lagoon, a nature trail and waterfront picnic tables.

Lovers Key is four barrier islands with a back-bay estuary that reliably holds manatees and bottlenose dolphins, both visible from the water and often from the bridge. The five-mile mangrove paddling trail is protected and shallow, and the tunnels are the kind of thing children remember. The beach is a walk from the parking areas - roughly a thousand feet over the mid-beach bridge - which keeps it quieter than the drive-up beaches nearby, but it also means carrying everything, so pack light with small children. The park took storm surge from Ian in 2022 and Milton in 2024 and services have not all come back the same: the tram is gone for good, and on-site rentals have changed hands. Bring your own boat, or ring ahead.

Piñones is a stretch of undeveloped coast just east of San Juan where a paved bike path and long wooden boardwalk run between the mangroves and the sea. Renting bikes and riding it is a genuinely good family morning - flat, shaded in stretches, with beaches and lookouts to stop at. The other half of Piñones is the food: a line of open-air kiosks cooking alcapurrias, bacalaítos and pinchos over charcoal, which is the best casual eating near San Juan and a real part of the island’s Afro-Puerto Rican culture. The Atlantic here has strong currents; swim only where locals are swimming.

Salt River Bay carries two distinct things at once. It is a national historic park because this is the single confirmed place where a Columbus landing party came ashore on territory that is now the United States, and it holds significant Taíno archaeology. It is also a bioluminescent bay, and guided night kayak tours run out into it around the new moon, when the dinoflagellates light up under the paddle. The mangrove estuary is protected and calm. Like every bio bay the experience is entirely moon and weather dependent, so book early in a trip to leave room to try again.