Puntarenas Province

Dive with huge schools of hammerhead sharks – plus manta rays and visiting whale sharks – at the world-famous Cocos Island, arguably the best dive site in the Eastern Pacific. June through October, they gather in uncountable numbers.

This marine national park off Uvita is one of the best places in the Americas to see humpback whales, with near year-round visits. You’ll also spot dolphins, Olive Ridley and Hawksbills turtles, boobies and pelicans.

The last remaining stand of coastal Pacific rainforest in Central America is the crown jewel in Costa Rica’s park system.

Spectacular and little-visited national park next to the wild Osa Peninsula, spread out around a deep-water tropical fjord.

One of Costa Rica’s most popular (and crowded) national parks, with easy-to-access, trail-cut rainforest (with abundant monkeys, lowland birds and smaller cats) backing a gently arching series of beaches. Editor: Alex has not done a full review as there are alot better options than this one.

Littered with strange pre-Columbian stone spheres and fringed with fish-teeming reefs, this little island reserve is easily visited from the Osa Peninsula.

550km off the Costa Rican coast, Cocos Island is a world-class dive site famous for huge congregations of rays which converge in the swirling currents welling up from deep water. Access is on 11-day live-aboard dive trips, from December to May, departing from Puntarenas.