The ascent to the summit of the Irazú Volcano is definitely one of the most popular excursions near Cartago, with spectacular drive through fields of coffee, potatoes and cabbages, replaced by dairy farms at higher levels. Set in its own national park, the Irazú Volcano rises to 3432m (11,260ft), the highest of the volcanoes around the Central Valley.
The geological history of Irazú Volcano over the past tens of millions of years has been deduced by geologists, but the first written record we have of its volcanic activity only dates back to 1723 when the Spanish Governor of Costa Rica, Diego de la Haya Fernández, chronicled an eruption that began in February of that year. It was a spectacular eruption that threw columns of smoke and ash into the air and sent chunks of incandescent rock rolling down the sides of the volcano, all accompanied by much noise and periodic seismic activity. Since then, there are accounts of a dozen other eruptions, some equally violent, others milder. The last series of events was from 1962 to 1965.
The summit has a complex of four craters, surrounded by swatches of dramatic volcanic ash. On top of Irazú you will find several deep craters in this barren windswept terrain that is reminiscent of a moonscape (like the Turrialba Volcano). Diego de la Haya crater – named after the Spanish governor – has a lake that is pea-green in color, tinted by minerals in the volcanic rock. A large adjacent crater is 300m (1080ft) deep, and another nearby crater is wide and shallow and covered with black volcanic ash, inviting comparisons with the surface of the moon. Irazú has erupted regularly over historical time. In August of 1962, Irazú began belching steam and by early 1963 it was producing such considerable amounts of ash and rock that people living and farming on the upper slopes had to be evacuated. The prevailing easterly winds eventually brought fallout of volcanic ash over much of the Central Valley, including the capital city of San José. It is said that the ash first began to settle on the city the same day in March of 1963 that the former U.S. President, John F. Kennedy, arrived in town to meet with the presidents of Central America and promote his regional economic development plan known as the Alliance for Progress – an ominous portent indeed. For the next two years, ash continued to drift down on the residents of San José and much of the rest of the valley making life very unpleasant and causing eye irritations and respiratory problems for many people. Finally, in March of 1965, this period of volcanic activity subsided and by 1966 a rock plug had solidified and blocked off the vent. Since that the Irazú Volcano has been fairly quiet, apart from its minor eruption in 1994, when some fumaroles activity occurred. Volcanologists speculate that Irazú Volcano has been erupting for over 500 years. It has recently entered a dormant phase to the great relief of farmers and property owners along the slopes.
The landscape of Irazú Volcano National Park is the only place in the Central Volcanic Range system that has Rainforest and Sub-Alpine Paramo – wind-swept, treeless plains situated from 10,827 to 13,124 feet. The vegetation around the peak is predictably stunted, with blackened dwarf oaks, ferns, lichens, cedar trees, interspersed with poor man’s umbrella plants and patches of scrubby grass add to the area’s otherworldly feel. Upon nearing the summit the destructive forces of volcanism begin to become more noticeable with the presence of scorched dead tree trunks that are still standing. The high elevation itself, being just above the tree line at this latitude, keeps the vegetation from growing very tall, but the periodic devastating effects of eruptions help to keep plant life rather sparse. In such an environment, wildlife is obviously scarce, but a few birds – the aptly named Volcano Junco, the Volcano Hummingbird, the Sooty Robin and Woodpeckers – manage to survive. You can also find coyotes, rabbits, weasels and armadillos
There is a ranger station 2km (1.25 miles) below the summit which has a restaurant with restrooms, a gift shop at the top in the parking area, a picnic site with tables, toilets and a mobile café, plus a small visitor’s center. Two trails lead from the car park to the summit. Good visibility is essential for a visit to Irazú Volcano, but don’t be deterred by an apparent shroud of fog – the summit is often above the clouds and bathed in splendid sunshine. On a clear day the views can be staggering and it is sometimes possible to see both the Caribbean and Pacific coasts. But don’t be fooled by the fact that Costa Rica is a tropical country; even here its cold at 3,400 meters with an average temperature on the summit of 7°C (45°F), overnight lows below freezing, so warm clothing is advisable. The wind chill on the summit can add to the sensation, too, so bring along several layers to assure comfort. The top of Irazú Volcano receives relatively little precipitation, with an annual average rainfall of just over two meters. The driest months are from December to April. The best time to view the craters is early in the morning, as cloud cover usually thickens after 10 a.m. Visitors during the dry season (December- April) are more likely to get clear views. A visit here is strictly a day trip, as there is no place to stay inside the park and camping is forbidden, but alternatively, visitors can book a full-day combo excursion that includes visits to Irazú, Lankester Botanical Gardens and the Orosi Valley.
Getting to Irazu Volcano National Park:
From San Jose, take the Pan-American Highway south to Cartago. Follow signs to the Irazu Volcano. There is a paved road that leads through the mountains and continues to the park where a small information center is located.
Take a bus from the route San Jose – Irazu Volcano, which takes about 1.5 hours (Buses Metrópoli, 2530-1064).
Location: 48km (30 miles) east of San Jose, in Cartago province.
GPS Coordinates: 9.978863,-83.835061 (9°58’37.20″N, 83°50’43.64″W)
Size: 2309ha (5705 acres)
Altitude: up to 3432m (11,260ft)
Schedule: from 8 a.m. to 4 p.m.
Irazu Volcano National Park Ranger station Telephone: +(506) 2551-9398
Central Volcanic Cordillera Conservation Area (ACCVC) Telephone: +(506) 2268-1587 / 2268-8091
INFOTUR Tourist Information: 1192