Costa Rica is a land of volcanoes. These volcanoes are part of the Central American volcanic arc and part of the Pacific Ring of Fire. Of the many volcanoes in Costa Rica, five are still active, Poás, Irazú, Arenal, Turrialba and Rincón de la Vieja. In the northwest of the country, Arenal is the most emblematic volcano in Costa Rica and the most active. It is located 56 miles northwest of San José. This stratovolcano has an almost perfect cone 5,436 feet high and with a crater 460 feet in diameter. Its shape reminds us of the famous Japanese volcano. In fact, it is sometimes called the Fujiyama of the Ticos. The Arenal Volcano National Park (Parque Nacional Volcán Arenal) was established in November 1991 and covers 46,81 sq. mi. The lake and the volcano are, of course, the main attractions. There is no lack of activities wandering in the primary and secondary rainforests, climbing on the lava flows, observing nature on the volcano’s slope and around Arenal lake, or relaxing in the natural hot springs in the Arenal Volcano National Park.
The Arenal volcano, a sulfurous history !
The Arenal Volcano National Park is located in the northwestern region of Costa Rica between the plains of San Carlos and the foothills of the Cordillera de Tilarán. Located halfway between the end of the lake and the small town of La Fortuna, the Arenal volcano can be seen from afar, very often with its head in the clouds. This stratovolcano is geologically considered a young volcano in Costa Rica. Its first eruption dates back 7,000 years. The volcano was then dormant for centuries, but on July 29, 1968, at 7:30 am, it erupted unexpectedly and violently. The mastodon went into tantrums, getting into a wave of black anger, or rather red incandescent anger. Its western slope exploded, burying over 5.8 sq. mi. under rocks, lava, and ashes. Fiery clouds covered the entire area. Some of the rocks thrown out of the volcano were the size of a car! During this extremely violent eruption, three villages (Tabacón, Pueblo Nuevo, and San Luís) were destroyed, and 87 people were killed. Three thousand two hundred eighty were left homeless, and 12,391 people declared disaster victims. The eruption continued for three days, creating three new craters on the western flank, respectively located at 3,478 feet, 3,838 feet, and 4,790 feet, and the main crater at the top of the volcano at 5,480 feet.
« A volcano ? A bad-tempered being, but without which the Earth would be very sad and very cold… Also a book whose barely burned pages tell the story of our beautiful planet so well. »
(Jacques-Marie Bardintzeff, Volcanologist)
For over 40 years now, the Arenal volcano has shown constant activity with lava flows and fiery clouds blowing large rocks and large amounts of ashes into the sky, all accompanied by deep rumblings. Contrary to what one might think, it is not the lava that causes the most damage during the eruption, but rather the pyroclastic clouds and flow, which are the most dangerous because of their strong destructive power and high velocity. This avalanche of ashes, rock fragments, and burning gas, whose temperature can reach several hundred degrees, moves without friction at speeds up to 435 mph. There is only a slight possibility of escape. No point in running; you need to get out ahead of time, as a certain Jean de La Fontaine would say. But how can we explain the speed of these clouds that carry thousands of tons of volcanic material over tens of miles? This question has intrigued scientists for a long time… Recently, a team of researchers from New Zealand, Australia, and the United States conducted large-scale experiments and numerical modeling, demonstrating that a layer of air develops at the base of the pyroclastic flow. The lubrication of the flow by the air allows the clouds to move almost without friction, explaining their remarkable fluidity and incredible speed.
From 1968 to the end of 2010, the Arenal volcano was sleeping with one eye open; periods of inactivity followed frequent eruptions, producing menacing ash emissions and streams of lava. Nowadays, you may not see the famed orange glow illuminating the night sky, but you can still see some fumaroles emanating from the top. The Arenal volcano seems to be resting but still has volcanic activity. Volcanologists and the OVSICORI (Costa Rica’s volcanological and seismological observatory) still warn of high volcanic risk. On the surface, the Arenal volcano today offers two images: one side plowed by ancient lava flows and on the other side covered by luxuriant vegetation in a palette of green ranging from the softest to the deepest tones. On the 1968 lava flow, the vegetation has had time to take over. On other more recent ones, the landscape resembles a river of petrified rock. Thermal springs emerge from the volcano, creating streams and pools of water with relaxing properties.
« And then, in a few aeons, the vegetation bloomed again, veiling with its lively gaiety the sinister expanse of grey ashes. Soon the memory of the catastrophe faded. Human memory can be incredibly short, and there is no volcanic region in the world where one has not, on several occasions, been surprised by the sudden awakening of a volcano presumed extinct only because it had been dormant for several centuries, or even just a few decades. »
(Haroun Tazieff – The Devil’s Blast)
Stay in the heart of mother nature in the Arenal volcano National park
Because 6% of the world’s biodiversity is in Costa Rica, the country has declared 25% of its territory as national parks, protected areas, or reserves. Today there are 29 national parks, the latest being the Miravalles Volcano Park, which was changed from a protected area into a national park in June 2019. To date, three parks are part of the UNESCO World Heritage: Cocos Island National Park (1997), La Amistad National Park (1983), and Guanacaste National Park (1999). With 46,81 sq. mi., the « Parque Nacional Volcan Arenal » was established in 1991. The park is located about 10 miles west of La Fortuna. It has incredible biodiversity, including more than half of the species of mammals, reptiles, and birds that can be observed in Costa Rica. For example, about 500 species of birds have been identified in the park, which is about 53% of all the birds in the country, making it a worthy destination for experienced and amateur bird watchers.
Even though the main attraction of the Arenal Volcano National Park is the impressive and majestic volcano of the same name, it often teases the visitor by often hiding behind a thick curtain of clouds. At an altitude of 5,436 feet, the almost perfect cone, a replica of Mount Fuji (12,389 feet), would make Hokusai, the master of Japanese prints, envious. But here, too, one must be patient because its conical silhouette is often covered by a veil of mist at the top. Not enough to disturb the cattle grazing in the vast pastures or the local cowboys known as sabaneros in charge of watching them. Set high on a ridge across the deep canyon of the Agua Caliente River, the Arenal Observatory Lodge is 1.7 miles from the south side of Arenal Volcano and is located within the Arenal Volcano National Park. In the 1970s, scientists from the Smithsonian Institute felt that this was an ideal place to study the volcano safely. The lodge is far from the dangerous western flank, and the deep and ever-flowing Río Agua Caliente (Agua Caliente River) protects the lodge from any danger of lava eruptions. The site seduced us from the start! From the terrace of the Arenal Observatory Lodge, we can watch the sun descend over the magnificent Arenal lake and its numerous small islands as the sky is flooded with the colors of fire that spread on the flank of the Arenal volcano and on the treetops in the forest. A moment of pure magic…
After enjoying the view of the volcano and perhaps even hearing it rumble a few times, you can start hiking on one of the many trails that line the primary and secondary forests of the park. A sign very well summarizes the philosophy of the hiker: « kill nothing but time; leave nothing but your footprints; take nothing but pictures ». It must be said that Costa Rica is a pioneer in environmental protection and has made its preserved nature and exceptional biodiversity a national showcase. In 1994, this small Central American country amended its constitution to state in Article 50, « Every person has the right to a healthy and ecologically balanced environment…» Briefly, it’s time for you to experience « Pura Vida »: enjoy the pleasure of discovering the riches of nature with a smile ! And to feel totally in the mood, listen to the beautiful song « Soy Tico » in a new version composed by Costa-Rican singer-songwriter Carlos Guzmán… 14 musicians and 11 national artists of different genres participate.
Are you ready, hiking boots on your feet, back bags, jam-packed with positive energy « Soy tico Porque llevo a Costa Rica en las entrañas » ? Then let’s go and enjoy the surrounding natural paradise. Many waterfalls are hidden in the middle of the lush vegetation, like the Danta waterfall (Tapir) near the Arenal Observatory Lodge or the Blue Morpho waterfall in Mistico Park. The air is fresh and humid, and the surrounding forest is filled with ferns and palms. At times, the trails are plunged into darkness as the vegetation absorbs the light. One feels almost like a stranger, an intruder as if one did not belong to this world. Only a few rare openings let the sun’s rays splash the ground. We meet some rare inhabitants: a basilisk (Basiliscus basiliscus), much less frightening than the one in Hogwarts; a Crested guan perched on a branch, looking for small berries; a Great female Curassow (Crax rubra) or Hocofaisán, which can hardly pass unnoticed at 31 inches in length and its 10 pounds in weight, its yellow bill, and its curly crest.
Contrary to what one might think, it is unnecessary to walk for miles to come across these rainforest natives. Staying silent, head in the air but also looking down to scrutinize the tree trunks to see a Green lizard looking a bit like Patrick Edlinger. Observe the smallest twig, bit of bark, or the slightest leaf on which can lurk a Red-eyed tree frog or a strange insect that could almost have been in the cast of the animated film « Minuscule 2: The Mandibles of the end of the world »… So, « Pura Vida » ?
Then at the bend, we find ourselves in bright sunny light on a bridge suspended in the canopy or in the middle of the fields, where cows rest peacefully, surrounded by white wading birds, also called Cattle egrets (Bubulcus ibis). Despite its name, the Cattle egret does not replace the shepherd dog and his master « sabanero » during their vacations… Cattle egrets are opportunistic feeders and typically forage in flocks often associated with grazing animals and pick off parasites on the large herbivores. Let’s the cattle grazing in the vast pastures to reach a forest of Honduran pines and rainbow eucalyptus. The eucalyptus deglupta (“Degluptere” in Latin) is a colorful tree. It can reach a height of 246 feet with a trunk up to 94 inches in diameter. Its smooth, orange-tinted bark sheds in strips, revealing a trunk that changes color with time: pale green, then blue, purple, orange, and finally purplish brown. Its trunk is a mosaic of colors giving the appearance of a rainbow. One would swear that a painter wiped his brushes on the trunk to create the incredible palette of colors. High perched nests occupy some branches of the rainbow eucalyptus. The nests of the Montezuma oropendola(Psarocolius montezuma) look like swings hanging from the branches. This crow-sized bird nests in colonies. There are typically about 30 nests in a colony, but up to 170 have been recorded. Some nests are under construction, and the transport of twigs is in full swing. Only the female builds hanging woven nests. The nest measures between 24 and 70 inches long. It is a beautiful sight to observe the constant coming and going of these weaver birds, bringing food and building materials. The other peculiarity of the Montezuma oropendola or Golden Pendulum is that it swings like a pendulum while passing its yellowtail over its head and singing.
Finally, it is difficult to talk about the Arenal Volcano National Park without mentioning the lake of the same name. It is the largest lake in Costa Rica, with an area of about 33 mi². Its depth varies between 100 and 200 feet seasonally. Lake Arenal was created in a volcanic caldera by a dam erected in the 1970s, immersing the old towns of Arenal and Tronadora, both now at the bottom of the lake. The new village of Arenal is on the northeast side of the lake. This artificial lake was used to meet the growing demand for water to irrigate crops on the Pacific side of the plain in Guanacaste and generate electricity for the country. Today, the dams and various windmills linked to Lake Arenal generate 70% of the country’s electricity. But the lake is also appreciated by fans of water sports (kayak, canoe, or paddle boat). It is always pleasant to discover the small creeks and inaccessible bays at the slow rhythm of a paddleboat with the benevolent cone of the volcano in the line of sight, flush out the fauna which inhabits them, like this Great egret. It is also one of the world’s top windsurfing and kitesurfing areas, as the winds average 45 mph. Finally, fishing enthusiasts can come and tease the Wolf cichlid(Parachromis dovii,) also known as the rainbow bass. This predatory fish can measure up to 28 inches. Suppose you are not interested in water sports. In that case, you can always get on a mountain bike to ride along the lake’s shores and train for the « Vuelta al Lago », a competition that takes place every year in March and brings together about 4000 cyclists. It takes two days to cover the 92 miles of road and trails.
Find more on Costa Rica
- Explore the cloud tropical forests of Costa Rica
- Costa Rica: A Vast Reservoir of Biodiversity
- Fauna and flora of the Arenal Volcano National Park
- Tenorio Volcano National Park, the most wonderful !
- The Caño Negro Refuge: Pointed teeth and Feathers along the Water
- The head in the clouds in the Reserve of Monteverde
- Exploring the Costa Rican Pacific coast: the Carara National Park
- Exploring the Costa Rican Pacific coast: the Manuel Antonio Park