Guanacaste is a large region; its numerous attractions are spread out and getting between any two major areas can eat up the better part of a day. The region is diverse enough to justify exploring in its entirety, for which you should budget no less than a week. Monteverde  alone requires a minimum of two days, and ideally four, to take advantage of all that it offers. Nor would you wish to rush exploring Rincón de la Vieja National Park , requiring two or three nights.
Recent years have seen a boost in regional tourism following expansion of the international airport at Liberia , now served with direct flights by most key U.S. carriers. The airport is well served by car rental companies.
The Pan-American Highway (Highway 1) cuts through the heart of lowland Guanacaste, ruler-straight almost all the way between the Nicaraguan border in the north and Puntarenas  in the south. Juggernaut trucks frequent the fast-paced and potholed road, which is one lane in either direction. Drive cautiously!
North of Liberia the route is superbly scenic. Almost every sight of importance lies within a short reach of the highway, accessed by dirt side roads. If traveling by bus, sit on the east-facing side for the best views.
Touristy it might be, but Monteverde , the big draw, delivers in heaps. Its numerous attractions include canopy tours; horseback riding; art galleries; and orchid, snake, frog, and butterfly exhibits. At Selvatura , the one-of-a-kind Jewels of the Rainforest Bio-Art Exhibition is worth the arduous uphill journey to Monteverde in its own right. Most visitors come to hike in the Monteverde Cloud Forest Biological Reserve , the most famous of several similar reserves that make up the Arenal-Monteverde Protection Zone.
Back in the lowlands, the town of Cañas  offers Las Pumas Rescue Center and the Río Corobicí: the former a refuge for big-cat species; the latter good for relatively calm white-water trips. To the north, few visitors make it to Volcán Miravalles , where several recreational facilities take advantage of thermal waters that also feed bubbling mud-pots and geysers. A side trip to Palo Verde National Park , with more than a dozen distinct habitats, is recommended for bird-watchers.
Nearby, Liberia  is worth a stop for its well-preserved colonial homesteads. The city is gateway to both the Nicoya Peninsula  and Rincón de la Vieja National Park , popular for hikes to the summit and for horseback rides and canopy tours from nature lodges outside the park.
Santa Rosa National Park  is more easily accessed from the Pan-American Highway and is popular for nature trails offering easy viewing of a dizzying array of animals and birds. It also has splendid beaches, great surfing, and La Casona, a historic building considered a national shrine.
The Cámara de Turismo Guanacasteca (tel. 506/2690-9501, www.letsgoguanacaste.com ), the Guanacaste Chamber of Tourism, is a good resource.