Isla Mata la Gata is the most-visited of La Parguera's mangrove cays — a tiny, sandy island ringed by waist-deep turquoise water. The bottom is sand and seagrass, the swimming is calm enough for kids, and a wooden dock and a few picnic shelters make it usable for a whole day.
Water taxis run from the village dock more or less continuously through the day and afternoon; you buy a return ticket and tell the captain when you want picking up. Bring everything you need — there is no food or drink sold on the island, just the beach, the shade and the snorkelling.