GUANACASTE NORTH PACIFIC AREA
Barra Honda
Unlike the volcanic stone found throughout northern Costa Rica, the Barra Honda area of the Tempisque Basin where the Nicoya Peninsula joins the mainland has a foundation of limestone. Water has cut extensive caves through the small limestone mountains of the park, and this is its best known feature. However, the park also has well maintained hiking trails. The protected tropical dry forest (though mostly secondary) within its borders is some of the last in the world, and very different from the rain and cloud forests that attract many ecological tourists to Costa Rica. 
The soda straws, pearls, roses, needles, cave grapes, curtains, terraces, stalactites, stalagmites and other calcareous formations of the more than 40 limestone caverns are the main attraction at Barra Honda National Park. The caves are all in relatively good condition because their vertical entrances are difficult to negotiate. This is also why you need climbing gear and permission from the Parks service in advance to enter them.
Rincón de Ia Vieja National Park
Palo Verde National Park
Rio Tempisque
Barra Honda
Check out out the Tours Southern Horizons Vacations has to offer: One Day Tours and Multi-Day Tours and Southern Horizons Vacation Packages.
Hotels: Platinum: Four Seasons Hotel, Paradises Conchal, Cala Luna, Fiesta Premier
Gold: Barcele Langosta, Tamarindo Diria, Hotel El Ocotal Beach Resort, Barcelo Tambor, Sugar Beach
Silver: El Milagro Hotel, Hacienda Cuachipelin