The Nicoya Peninsula is a broad, hooked protuberance—130 kilometers long and averaging 50 kilometers wide—separated from the Guanacaste plains by the Río Tempisque and Gulf of Nicoya.

Known for its magnificent beaches and a long dry season with sizzling sunshine, it’s the epicenter of beach-based vacations in Costa Rica. Most tourist activity is along the dramatically sculpted Pacific shoreline. Away from the coast, Nicoya is mostly mountainous.

More than three-quarters of Costa Rica’s coastal resort infrastructure is in Nicoya, concentrated in northern Nicoya. Since the opening of the Daniel Oduber International Airport in 1996, scores of resort hotels (and three golf courses) have sprouted, tilting the demographics away from eco-conscious travelers and toward a more high-end crowd.

Residential condo complexes have also sprung up, numerous as palm trees beside a damp beach. Aquifers are being drained, water pollution is rising, and wildlife is disappearing. In all, an ecological disaster is playing out, say alarmed environmentalists, due in part to government inaction in the face of developers who simply don’t care.

Though each beach community has its own distinct appeal, most remain barefoot and button-down, appealing to laid-back travelers who can hang with the locals and appreciate the wildlife that comes down to the shore.

This is particularly so of the southern beaches. Waves pump ashore along much of the coastline—a nirvana to surfers, who have opened up heretofore hidden sections of jungle-lined shore. Newly cut roads are linking the last pockets of the erstwhile inaccessible Pacific coast, though negotiating the dirt highways is always tricky—and part of the fun.

Predominantly dry to the north and progressively moist to the south, the peninsula offers a variety of ecosystems, with no shortage of opportunities for nature-viewing; monkeys, coatis, sloths, and other wildlife species inhabit the forests along the shore. Two of the premier nesting sites for marine turtles are here. The offshore waters are beloved of scuba divers and for sportfishing, and water sports are well developed.

The downside, besides the immense overdevelopment of condominium projects, is skyrocketing crime.

The Best of the Nicoya Peninsula

• Guaitíl
• Tempisque Safari Ecological Adventure
• Marino Las Baulas National Park
• Ostional National Wildlife Refuge
• Nosara
• Flying Crocodile Ultralight Flight
• Isla Tortuga
• Cabo Blanco Absolute Wildlife Reserve
• Santa Teresa and Malpaís