Seismic and volcanic region
Behind a nature as beautiful as captivating, Costa Rica is a land in turmoil, hiding a primitive violence characterized by earthquakes, volcanic eruptions and hurricanes. Why so much turmoil? Because of its geological origin, Central America is one of the most seismically active regions in the world. It all began 65 million years ago: during an intense seismic activity, the region saw two tectonic plates collide. This is how Central America emerged, located on the Pacific Ring of Fire that runs from Alaska to Patagonia. The subduction of the Pacific plate (Cocos plate) under the continental plate (North American plate) has led to the creation of a long chain of volcanoes over the whole western part of the region. Thus, the peaks of the central cordillera, which appeared in the upper Miocene as islands, are one of the oldest formations in this country. As proof, many marine fossils have been identified. Today, a mountain range crosses Costa Rica from northeast to southwest. It is composed of three parts: in the north the Guanacaste mountain range and its famous Arenal volcano culminating at 1,630 meters above sea level, the Tilarán mountain range, which joins the Guanacaste mountain range to the central volcanic range, and the Talamanca mountain range, one of the most interesting for geologists even though it has no volcanoes. It is composed of a very dense and ancient forest, with fifteen of its peaks exceeding 3,000 meters.
Land of fire
Costa Rica has at least 290 volcanoes, some of which are extinct, others dormant, and only 5 historically active. Important eruptions have occurred such as Turrialba volcano in 1864, Poás in 1953 and 1955, Irazú in 1963 and 1965, Arenal in 1968, and Rincón de la Vieja in the 1990s. These fire breathers have caused violent and disastrous eruptions, often leaving a tragic memory. Characterized by phreatic eruptions, Irazú, Turrialba or Poás are famous for their explosions of rocks projected up to hundreds of meters.
The Turrialba volcano, with its 3,339 meters, is one of the most watched volcanoes in Costa Rica: every day, one of its three craters spits clouds of smoke. After more than 150 years of sleep, the volcano has been very active since 2016 which has led to careful observation by scientists ever since.
Although often hidden in the mist, the Poás offers to the eye its crater lake and its fumaroles. At 2,704 meters above sea level, its 1.7 km crater is considered the largest in the world. The great eruption of 1910 and the column of water and mud that it projected to more than 4,000 m of altitude remain in the collective memory: ashes were deposited until Puntarenas! Since 1928, the volcano has experienced nearly 40 eruptive episodes. The last recorded eruption was in 2019, but in April 2017, repeated eruptions forced the park to temporarily prevent access to the crater.
Culminating at 3,432 meters above sea level, Volcan Irazú is an active volcano with a heavy eruptive history. Its eruptions are accompanied by clouds of steam and jets of ash, slag or stones. Its last eruptions date back to 1991 and only a few fumaroles are currently visible. Its summit has four craters: the main one presents a lunar landscape on 1,050 meters in diameter; Diego de la Haya, the second one, was home to a sulfurous lake until 2014: the lagoon began to evaporate with the resumption of volcanic activity, but it is gradually reforming since 2017. The other two craters are located on either side of the main crater.
Arenal, with its iconic perfection, embodies the archetypal volcano. Its main crater measures 1,300 meters in diameter and 300 meters deep. Because of its 3,000 years of inactivity, people have lived near this mountain for a long time without ever thinking that it could present a danger. But in 1968, during a violent earthquake, this young fire-breather came out of its sleep. Since then, these eruptions, minimal, are not of great danger: the last big eruption goes back to 1993. According to vulcanologists, the volcano is showing signs of a rest cycle, which means that it is beginning to go back to sleep.
Finally, the Rincón de la Vieja volcano, which is more than one million years old, made the news in 2021 when it last erupted. This last eruption lasted only three minutes, but sent a 2 km column of gas and ash into the sky. Since the arrival of the Europeans in the 16th century, the eruptive activity of Rincón de la Vieja has occurred regularly; about 20 eruptions have been recorded, mainly in the period 1966-1970 and 1991-1992. It is currently the third most active volcano in Costa Rica, with nine interconnected eruptive cones, one of which - the main crater - is permanently active. It behaves like a pressure cooker with several nozzles that let out steam. South of the giant, in places called "Las Pailas" (thistles) and "Hornillas" (small ovens), geysers and steam jets containing sulfur, iron and copper have colored the surroundings with "impressionistic" red, yellow or green spots.
In search of landscapes
All these sights, which shape the landscape and mark the surface of the country, can be observed as you discover the different areas of Costa Rica. The country is a field of choice to enjoy the reliefs in any season. The change of scenery can be overwhelming! In front of some panoramas, the emotions are jostled and the senses are awakened.
On the Pacific side, from the north to the south of the west coast, the landscape is multiple: the heat and the dryness are severe in Guanacaste while following the coast, we approach the western flank of the Nicoya peninsula, where the beaches follow one another until Playa Carillo, first point of access when we go down from the mountains of the center of the peninsula. To the south of Nicoya, going up to the gulf of the same name, there are rocky coves, still wild. Going down to Quepos, we find beaches and the famous Manuel Antonio National Park. Remote and still difficult to access, the Osa Peninsula and its immediate surroundings occupy less than 0.001% of the Earth's surface, but are home to 2.5% of its life forms. The variety of habitats in Osa offers refuge to thousands of species between cloud forests, swamps, freshwater lagoons and mangroves.
On the other side, to the east, the coastline is bordered by the Caribbean Sea. Just after the central mountain range and its forests hidden by the clouds is Tortuguero, an immense lacustrine expanse, relatively isolated. It is the privileged place of the green turtles which chose these beaches to come to lay their eggs from May to August.
To the north, the Frío and Sarapiquí rivers take us to Nicaragua, while a little further south, the waterfalls of La Fortuna and the hot springs of Tabacón bear witness to the volcanic activity of the Arenal volcano. Most of the volcanoes here have hot springs, thermal baths that attract tourists and locals alike. To the northwest, the majestic Rincón de la Vieja and the no less majestic Arenal are there to remind visitors of the ongoing volcanic activity of the Central American Isthmus. The waterfall of the Río Celeste is particularly spectacular: the presence of aluminum silicate gives it an incredible color. To better understand the origins of this celestial blue, it is necessary to go upstream the history of this forest, it is a unique chemical phenomenon which occurs at the level of the meeting point between the Quebrada Agria, which has an acid PH, and the Buena Vista river which is charged in particles of aluminum silicates. The acidic water increases the size of the mineral particles while others remain in suspension, reflecting the bewitching blue light. The cloud forest of Monteverde, Lake Arenal and the beaches of the North Pacific complete the extraordinary palette of natural riches of this region.
The southwest and its high mountains offer an unspoiled landscape, more spared from human activity. On the slopes of the Cordillera de Talamanca, we find a particular geography where periods of glaciation have left their mark in the heart of incredibly dense tropical forests. Always towards the west, the Tanpiscué river flows, it is a whole wetland area protected by a national park. The Palo Verde is home to a multitude of birds, sedentary or migratory, they find food and refuges to reproduce. Lagoons, mangroves and swamps form a unique ecosystem in this area of the country. Traveling through these lands shaped by Mother Nature is a real privilege: at the whim of the relief, one discovers coral reefs, volcanic silhouettes, waterfalls with perfect clarity or tropical valleys. From one surprise to another, such discoveries will surely make you want to explore the most beautiful natural sites of the country.
National parks, natural jewels
Volcanoes, mountains, rivers, forests, mangroves, oceans... A paradise must have a setting, these are the national parks and reserves that guarantee the visitor a total wonder. The country's well-guarded treasures can be observed, explored and rediscovered within the natural parks: more than a quarter of the country is concerned. Intact forests, there are some national parks where you can visit and stay for days. Rafting, hiking, canoeing. Natural parks have been created, coupled with private reserves. In Manuel Antonio National Park, the visitor will be sure to see animals: sloths, capuchins, toucans. Bordered by three magnificent beaches, this park is the most visited in the country. Since the creation, in 1963, of the first national park in Cabo Blanco, then in 1970 of the National Parks Service within the Ministry of Agriculture, Costa Rica has not ceased to increase the importance of these zones which protect between 6 and 10% of the totality of the plant and animal species of the world. Today, the country has 30 national parks, 149 protected wilderness areas, 58 wildlife refuges, 32 protected areas, 15 wetlands, 11 forest reserves and 8 biological reserves. Almost all existing habitats are present: deciduous forests, swamps, mangroves, rainforests (also called tropical rainforests), cloud forests, herbaceous lagoons, swamp palm groves, tropical dry forests and desert areas. But how do you tell the difference between each so-called protected area? National parks protect natural resources, mostly primary forests, i.e. never touched by man. One can follow trails, guided or not, and participate in discovery or maintenance activities. Biological reserves are forests or forest lands where all forms of forest life are preserved and are generally inaccessible to the general public. The national refuges, with delimited areas, protect the fauna and flora of the forests and more particularly threatened species. Finally, the forest reserves have been developed on lands dedicated to large forest plantations, especially teak, which have adapted very well to Costa Rica. For the swamps which are the habitat of many plant and animal species, these flooded lands or partially covered by water are allowed to have or keep certain human activities as long as they have no impact on the environment. Many protected areas have thus been able to maintain their natural beauty. Costa Rica jealously guards its parks and the enormous economic potential they hold, a wealth made possible by a benevolent climate and a special geographical location. Three sites are listed as UNESCO World Heritage Sites: the Amistad Reserve (1983), Isla del Coco National Park (1997) and Guanacaste National Park (1999). All these protected areas are now connected by ecological corridors that allow free movement of animals.
