Guanacaste Conservation Area is in the northeastern cantones (counties) of Liberia, La Cruz, Bagaces and Upala, spanning between the provinces of Guanacaste and Alajuela. This area comprises three national parks: Rincón de la Vieja Volcano NP, Guanacaste NP and Santa Rosa-Bolaños island NP, the recreational area of Junquillal, Horizontes experimental station and some smaller protected areas.

The particularity of this part of the country, regarding the rest of the country, is it´s drier climate to the pacific side of the mountain slopes. So, it´s considered the last relict of the dry tropical forest that sometime covered from Guanacaste to southern Mexico. With this respect, it´s the largest area to include such forest. It also has some other important aspects: the large biodiversity that it houses, somewhat different to what is usual in the wetter parts of the country, the savanna-type vegetation, the presence of different species such as: deers, coaties, monkeys, armadillos, snakes, etc. The marine part is also particulary rich and pristine in terms of biodiversity.

Bolaños island is considered a sanctuary for marine birds, Junquillal and Naranjo beaches are extremely appreciated for their waves and rugged landscape, Santa Elena peninsula in Santa Rosa NP is the driest and geologically oldest part in the country and it´s in a great deal untammed by human action, Murciélagos islands are also representative of the historic and biological evolution of the area. Santa Rosa has the biggest section of dry forest, a mariine area, and coastal marshlands, and also has Nancite Beach, one of the most important beaches for sea turtles spawning in the Pacific Ocean.

Santa Rosa is also important for costaricans is also representative of the country´s history for Santa Rosa hacienda, that even when it´s a reconstruction of the original hacienda (burnt in 2001), it´s stock corrales and the sites of three diferent battles (especially that one of 1856 when an unprepared costarrican army defeated a group of mercenary invaders from the southern states of the USA) are of great autenticity by their historical importance and representative of the history of Guanacaste as an area for cattle ranches.

In terms of the importance of the ongoing biological processes, Guanacaste NP is the most important of the three, covering from the steppe-like vegetation on the pacific slope, to the high peaks of Orosi and Cacao Volcanoes, to the wet parts facing the Caribbean side. Rincón de la Vieja is well known as a park with two high volcanoes, a series of hot springs, mud volcanoes and other volcanic formations, a rich forest bordering pristine rivers and waterfalls, acid lagoons and other impresive landscapes.

As a conservation area, Guanacaste is unique for it´s climate, the dry forest and the contiguity of all the areas, that makes easier the biological exchange among the areas. Even when threatened by stational wildfires and hunting, this area represents a microcosm of the variety of protected areas in this country.