8 Best Sights in Guanacaste and the Nicoya Peninsula, Costa Rica

This wildlife refuge protects one of Costa Rica's major nesting beaches for olive ridley turtles. If you get to go when the turtles are hatching, it is a magical experience. Locals have formed an association to run the reserve on a cooperative basis, and during the first 36 hours of the arribadas (mass nesting) they are allowed to harvest the eggs, on the premise that eggs laid during this time would likely be destroyed by subsequent waves of mother turtles. Though turtles nest here year-round, the largest arribadas, with thousands of turtles nesting over the course of several nights, occur from July to December; smaller arribadas take place between January and May. They usually occur around high tide, the week of a new moon. It's best to go very early in the morning, at sunrise. People in Nosara can tell you when an arribada has begun, or check the Facebook page Asociacion de Guias Locales de Ostional (AGLO) Costa Rica. To avoid overcrowding on the beach, visitors must join a guide-led tour of the nesting and hatching areas for $20 per person. Stop at the kiosk at the entrance to the beach to arrange a tour, or at the Association of Guides office, 25 meters (82 feet) south of the beach entrance on the main road, next to Cabinas Ostional. A new bridge over the Río Montaña has made access easier from Nosara, but it's sometimes difficult to get to from the north during rainy season (May to mid-December).

A mecca for speleologists, the caves beneath the 1,184-foot Barra Honda Peak were created millions of years ago by erosion after the ridge emerged from the sea. You can explore the resulting calcium carbonate formations on a guided tour, and perhaps catch sight of some of the abundant underground animal life, including bats, birds, blindfish, salamanders, and snails. The caves are spread around almost 23 square km (9 square miles), but many of them remain unexplored.

Every day starting at 8 am, local guides take groups 58 feet down ladders into Terciopelo Cave, which shelters unusual formations shaped (they say) like fried eggs, popcorn, and shark's teeth. You must wear a harness with a rope attached for safety. The tour costs $30 per person (minimum of two) including equipment rental, guide, and entrance fee. Kids under 12 are not allowed into this cave, but they can visit the kid-size La Cuevita cavern ($5), which also has interesting stalagmites. Both cave visits include interpretive nature hikes. The caves are not open during the wet season for fear of flooding.

Those with a fear of heights, or claustrophobia, may want to skip the cave tour, but Barra Honda still has plenty to offer, thanks to its extensive forests and abundant wildlife. You can climb the 3-km (2-mile) Los Laureles trail (the same trail that leads to Terciopelo Cave) to Barra Honda's summit, where you'll have sweeping views over the surrounding countryside and islet-filled Gulf of Nicoya. Wildlife you may spot on Barra Honda's trails include howler and white-faced monkeys, skunks, coatis, deer, parakeets, hawks, dozens of other bird species, and iguanas. It's a good idea to hire a local guide from the Asociación de Guías Ecologistas. The park has camping facilities ($2 per night), and the ranger station, open 8 am to dusk, has potable water and restrooms. There are also a couple of basic cabins to rent ($30).

Established by former farmer and logger-turned-conservationist Frederico Schutt in 1933, this 106-hectare (262-acre) refuge is named after the indigenous word for the spiky-barked pochote trees that flourish here. The reserve is home to hordes of phantom crabs on the beach, howler and white-faced capuchin monkeys in the trees, red brocket deer grazing in open fields, and plenty of hummingbirds, kingfishers, woodpeckers, trogons, and manakins (including the bird-watcher's coveted long-tailed manakin). The refuge, classified as a Blue Flag project, is working on building an artificial reef. Visitors can stay in very basic beachfront cabins with solar power ($30 per person, including entrance fee); meals are $10 each. Call ahead to arrange for lodging or horseback rides ($15 for one hour; $25 for three-hour tour). Kayaking tours and early-morning bird-watching walks are organized by Turismo Curú. The entrance fee to the reserve is $13.

This idyllic, unpopulated island has a white-sand beach fronting clear turquoise water, where you'll see a good number of colorful fish, though in the company of many tourists, arriving in many boats of all sizes; try to avoid the weekends if you can. A 40-minute hiking trail (small fee) wanders past monkey ladders, strangler figs, bromeliads, orchids, and the fruit-bearing guanábana (soursop) and marañón (cashew) trees up to a lookout point with amazing vistas. Amenities: food and drink; toilets; water sports. Best for: snorkeling; swimming.

This modest collection of mostly rescued small animals offers a great chance to see them up close in chest-high corrals under the shade of trees and shrubs. The Italian owners are a little eccentric, and the place is not terribly well kept. There are plenty of usually hard-to-see nocturnal animals, so the best time to visit is just before sunset, when the roly-poly armadillos and big-eyed kinkajous are starting to stir. There are also skunks, spotted pacas, raccoons, bats, and scarier species like boas, poison dart frogs, caimans, and crocodiles. A bromeliad and orchid collection is artistically arranged around the zoo. If you come early in the day (the best time to see the day animals in action) your ticket is also good for a return early-evening visit. It's pricey, but the ticket price helps to buy food for the animals. Crocodile feeding time is every Tuesday and Friday at 5 pm.

This wide swath of light-brown sand stretches over 3 km (2 miles), with coconut palms lining much of it and hardly a building in sight. Two species of sea turtle nest here, and a group of young people collect and protect their eggs, releasing the baby turtles after sunset. The surf is a little strong, so watch children carefully. There's a kids' playground right at the beach, and a funky little restaurant with concrete tables amid the palms. At low tide, it's a perfect beach for taking long, romantic strolls or for exploring active tide pools. Surfers head here to ride the beach break near Junquillal's northern end because it rarely gets crowded. Amenities: food and drink. Best for: surfing; walking.

On the southern end of Culebra Bay, this calm beach with black sand stretches 2 km (1 mile), and is frequented by guests staying at nearby El Mangroove resort and Casa Conde Beachfront Hotel. It's a great beach to visit with kids if you're staying in nearby Play Del Coco as well. Devoid of rocks and waves, the water is virtually flat, making this a popular spot for stand-up paddleboarding, kayaking, and swimming. There’s a wooden shack next to El Mangroove offering overpriced water activities and equipment. Local vendors stand beachside, selling everything from sarongs to snow cones. With a minimum of six people, you can organize a snorkeling tour on a boat to the outer bay. There isn’t much shade on the sand, but a grassy area between the resorts and the beach is lined with swaying palms and mesquite trees. A path meanders from one end of the bay to the other, meaning you can stroll without getting too much sun. There's guarded parking ($1 tip) between the two hotels. Amenities: food and drink; water sports. Best for: kayaking; swimming; walking.