Río Celeste Waterfall Hike & Swim brings you deep into Costa Rica’s Guanacaste Province, inside the cloud-wet corridors that drain from Tenorio Volcano National Park. This full-day, eight-hour outing pairs a rainforest trek to the famed Celeste River with a cooling plunge at Llanos de Cortés, offering both the sculpted blue waters visitors come for and the raw, green terrain that feeds them. The core of the trip is the Celeste River and its waterfall—an otherworldly turquoise chute where two clear streams meet and trigger a chemical reaction that scatters sunlight into the river’s signature blue. The waterfall drops through volcanic rock over polished boulders to a pool framed by primary forest; nearby the blue lagoon and river gorge reveal mineral-stained stones and thick stands of heliconia and strangler fig. Guides lead a challenging rainforest hike on switched trails of roots and rock, stopping to interpret the ecosystem: leafcutter ants marching columns, toucans calling from the canopy, and the occasional slipper frog hidden among moss. Before or after the hike this itinerary includes Llanos de Cortés, a broad, sandy-bottomed cascade ideal for a supervised swim—clear, shallow pools with warm current eddies that make for an easy, restorative dip. The contrast between the soft plunge pools at Llanos and the cool, no-swim sanctity of Celeste’s lagoon underscores why this region is special: volcanic geology and rainforest hydrology combine to make landscapes and waterways you won’t find elsewhere. Local guides emphasize stewardship; paths are narrow and sensitive, and access is limited to protect the chemical balance that creates the river’s color. That expert-led context turns a hike into something more than a photo op: it’s a lesson in how groundwater chemistry, volcanism, and forest health interconnect. The trip includes an authentic Costa Rican lunch and transportation from Guanacaste coastal pickup points, making the logistics easy for visitors based in Flamingo, Tamarindo, or Playas del Coco. Who should book this? Hikers with solid footing and a sense for wet tropical trails, families with older children (minimum age varies), and anyone who wants both a proper swim and a chance to see one of Costa Rica’s most unusual rivers. Expect uneven terrain, changing weather, and unforgettable blue water that looks impossible until you stand beside it. Bring a camera with a polarizer to cut glare, quick-dry layers for humidity, and biodegradable sunscreen to avoid contaminating the water. Guides often time the walk to avoid crowds, but weekends and holiday mornings can still be busy. If you love geology, birds, or river-swimming, this is a high-value day trip from Guanacaste’s coastlines. Book through a licensed operator to ensure permits and park support are in place. Expect memorable blue water, rainforest lessons, and lasting outdoor memories.