The scent arrives before the city: a fragrance of damp vegetation, warm earth and ripe fruit that drifts all the way to the deck as you enter the harbour. Puerto Limón, Costa Rica's main Caribbean outlet, is no polished calling card; it is a door wide open onto one of the most biodiverse countries on the planet. The terminal is a five-minute walk from downtown, but for many passengers, the day will play out elsewhere, on the waters of the lagoons or deep in the jungle.

A Creole, straightforward downtown

Before or after the excursion, the grid of about ten streets that makes up downtown is worth a stroll. Parque Vargas, planted with huge palm trees, borders the waterfront; looking up, you may sometimes spot a sloth hanging from the branches, a first contact with local wildlife without leaving the sidewalk. Around it, the municipal market overflows with pineapples, mangoes and unfamiliar root vegetables, while the sodas, small family-run restaurants, serve rice and beans simmered in coconut milk and spicy patí, signatures of the province's Afro-Caribbean culture. Offshore, the islet of Uvita recalls a founding episode: Christopher Columbus dropped anchor there in 1502, on his final voyage to the Americas.

The Tortuguero canals, a miniature Amazon

The most popular excursion leaves from Moín, a few kilometres from the terminal. Flat-roofed boats venture into a network of waterways lined with dense vegetation, where the guide regularly cuts the engine. Then the lagoon begins to speak: howler monkeys whose cries roll like distant thunder, toucans, caimans motionless at the waterline, herons taking off in a rustle of wings and sleepy silhouettes curled up in the forks of trees. Two to three hours are enough to understand why Costa Rica has made nature conservation part of its national identity, with a quarter of its territory under protected status.

Rainforest and sloths up close

About 45 minutes away by road, the Veragua reserve combines canopy walkways, a hummingbird garden, a vivarium of enamel-coloured frogs and an aerial tram that descends into the heart of the vegetation: a structured immersion, ideal for families. Farther south, a sanctuary rescues and cares for orphaned or injured sloths before releasing them; the guided tour lets you see the country's two species, two-toed and three-toed, up close. Finally, beach lovers will aim for Cahuita, where a coastal trail separates the golden sand from the tall trees, with a good chance of meeting capuchin monkeys and crab-eating raccoons.

Good to know

• The U.S. dollar is widely accepted; the colón remains the national currency.
• Equatorial climate: showers are possible in any season, so a light raincoat is recommended.
• Book nature outings early: morning departures offer the most active wildlife.
• Insect repellent and closed-toe shoes are useful for forest trails.
• Souvenirs: regional coffee and local chocolate can be found at the craft market set up near the terminal.

At the end of the day, as the ship pulls away from the coast, the green remains imprinted in your eyes: that of the lagoons, the canopy and the hills closing off the horizon. Puerto Limón does not hold you with its monuments, but with this animal and plant life that spills over everywhere and makes you want to come back to explore the country far beyond its Caribbean façade.