The Central Pacific [1] zone is predominantly a beach destination favored by surfers: Playa Hermosa [2] and Dominical [3] are their favored haunts. The area is easily explored along the coast highway, with side roads branching off into the mountains or beaches. Allocate at least a week to explore the entire region north to south. Three days is sufficient if you wish to concentrate on either Manuel Antonio, Jacó, or Dominical.
The most developed of the beach resorts is Jacó [4], long a staple of Canadian package charter groups but also an in-vogue destination for surfers, Tico youth, and sportfishing enthusiasts. If you like an active nightlife this is also for you, but I find the place overrated; the beach is simply awful, and the drugs and prostitution scene is now disturbingly overt. If quality is your gig, head to Manuel Antonio, being sure to call in to dine at Villa Caletas, one of the finest hotels in the country.
The best-known and most beautiful beaches are those of Manuel Antonio National Park [5], just south of the sportfishing town of Quepos [6]. Together they boast scores of accommodations (Manuel Antonio is more upscale; Quepos caters to the budget end). Clear waters and a coral reef make Manuel Antonio a favorite of snorkelers, while a lush tropical forest with well-groomed nature trails and abundant wildlife makes this one of the most visited parks in the nation.
Carara National Park [7] also offers a feast of wildlife wonders and has the advantage of being accessed direct from the coast highway (the Costanera Sur). Want to go croc-spotting? Sign up for a crocodile safari on the Río Tárcoles [8]. Kayak trips in search of dolphins and whales are a popular option along the coast further south.
Other facilities worth a call include Rainforest Adventures, with a gondola ride through the rainforest canopy. The Santa Juana Mountain Tour [6] offers a chance to interact with a mountain community, integrated into an ecotourism project that is a model for how things should be done.
Links:
[1] http://www.moon.com/destinations/costa-rica/central-pacific
[2] http://www.moon.com/destinations/costa-rica/central-pacific/jaco/playa-hermosa
[3] http://www.moon.com/destinations/costa-rica/central-pacific/costa-ballena/dominical
[4] http://www.moon.com/destinations/costa-rica/central-pacific/jaco
[5] http://www.moon.com/destinations/costa-rica/central-pacific/quepos-and-manuel-antonio/manuel-antonio-national-park
[6] http://www.moon.com/destinations/costa-rica/central-pacific/quepos-and-manuel-antonio/quepos
[7] http://www.moon.com/destinations/costa-rica/central-pacific/orotina-playa-herradura/carara-national-park
[8] http://www.moon.com/destinations/costa-rica/central-pacific/orotina-playa-herradura/jungle-crocodile-safari