The volcano is located in the extreme northwest of the national park of the same name, which was founded in 1995 and covers an area of 12,871 hectares. It is famous for its thermal springs with temperatures up to 94°C and bubbling mud pools. In the lower border zones of the Tenorio National Park, large macadamia plantations expand. At the foot of the volcano stretches the valley of Bijagua, from where one should undertake the possible ascent only with a local guide, since there is no route. The climate of the national park is influenced by the Pacific and Atlantic with eight different climate zones. The temperature varies between 15° and 24° C with an average annual rainfall of 4000 mm. The park owes its diverse ecosystems to these different climate zones, with a correspondingly large variety of flora and fauna. The local flora includes various palm species, heliconias, bromeliads and orchids as well as wild avocado trees, sapotes, oaks, netannons and trumpet trees (bignoniaceae). The endemic Jícaro de Danta (Parmentiera valerii), an endemic species in the Cordillera of Guanacaste, occupies a special position. Its fruits, which grow directly on the trunk, are the main food for tapirs (danta). Accordingly, a growing number of tapirs belong to the local fauna, as well as puma, wild boar, tree ocelot, grey fox, red deer, monkeys, agutis and over 300 different bird species. The Tenorio volcano has four cones and two twin craters. Its flanks are lined with mixed forests, crossed by primary forests, while savannah and tropical dry forest dominate in the deeper regions of the dry side.

The Rio Tenorio has its source on the west flank of the volcano and the Rio Tenorito and Rio Martirio on the south flank. On a clear day you can see the lowlands of San Carlos and Guatuso, Lake Arenal and Lake Nicaragua from its summit. The main attractions of the national park are the picturesque waterfall and lagoon, the sky-blue Rio Celeste, which owes its unreal colour to mineral deposits, the beautiful panoramic view to Lake Nicaragua, hot steam and thermal springs, and the crystal-clear streams along the hiking trails. The hiking trail called “Misterios del Tenorio” is particularly recommendable. It is 3.5 kilometres long and takes about three hours (without bathing breaks). A suspension bridge system of the Lodge “Las Heliconias”, operated by a local cooperative, leads through the treetops of the rain forest. In addition, all hotels arrange rafting tours on the Rio Tenorio (class 3 to 4, one spot class 5), and “River Floating” (rafting class 1 to 2) as the more peaceful option on the Rio Corobici.