Cahuita National Park occupies the headland immediately south of the village and a stretch of coast beyond it. The Kelly Creek entrance at the southern edge of town is the most convenient starting point — walk through it and you are immediately on Playa Blanca, a long beach of white sand shaded by palms, with forest on one side and the Caribbean on the other. A trail runs the full length of the park, about 8 km to the Puerto Vargas campsite and entrance, passing through lowland rainforest thick with howler monkeys, sloths, and coatis. The forest makes easy wildlife viewing: the animals here are used to people and tend to go about their business.
The reef at Punta Cahuita, at the end of the headland, is the park's main draw. The snorkelling here is good rather than spectacular — expect parrotfish, angelfish, eels, and the occasional sea turtle, along with coral formations at shallow depth. Visibility depends heavily on rainfall upstream: heavy rains in the Talamanca mountains wash sediment down through the Estrella and Sixaola river systems and into the sea, reducing visibility for days at a time. The best snorkelling is typically during the drier months, February through April.
Entry at Kelly Creek costs nothing — a donation is requested and worth paying. The Puerto Vargas entrance on the far side of the park charges a standard national park fee. You can snorkel independently or hire a local guide and boat in the village, which gives access to parts of the reef you cannot reach on foot. Bring your own mask and fins if you have them; rental gear in town is available but quality varies. The trail is flat and easy, but wear something you don't mind getting muddy after rain.