Location
Cartago Province.
Altitude
3,432 meters (11,260 feet)
Description
Irazu Volcano
Irazu Volcano National Park is situated in the Central Volcanic Cordillera. An asphalted road runs the 32 km from Cartago almost to the edge of El Principal and Diego the la Haya. There is a look-out point for views of El Principal crater. Visitors are not allowed to walk through areas marked as high risk or go down into the craters. Two kilometers before arriving the craters, there is an information stand and a picnic area with tables, toilets and drinking water. There is a bus service on Saturdays and Sundays from San Jose and Cartago. Along the access road to the park there are hotels, restaurants and grocery shops.
Irazu at 3,432 meters above sea level, is the tallest volcano in Costa Rica. The active volcano has a long history of eruptions and eruptive cycles. The protected area's many geological features include the Playa Hermosa, Principal and Diego de la Haya craters, as well as the Sapper formation, the highest point in the massif, from which both Caribbean and Pacific coasts may be seen. The unusual bright greenish yellow coloring of the lake at Diego de la Haya Crater is caused by rainfall dissolving the minerals along the craters walls. The lake is also closely monitored for changes in chemistry and temperature.
The Irazu Volcano is an active strato volcano with an irregular sub conical shape at 3,432 meters above sea level and over 500 square kilometers of forest. At the top, there are three main craters. El Principal is almost circular, 1,050 m in diameter and 250 to 300 m deep. At its base, there is a temporary lagoon with greenish yellow water. Another crater is called Diego de la Haya, which is circular, 690 m in diameter and 80 m deep. It is blocked and rainwater frequently collects in the flat bottom, forming a small lagoon. These two structures are partially surrounded on the southern side by the remains of the giant crater of a caldera. Two other small craters are located to the southeast of the first one. On the flanks of the volcano two parasitic cones can be seen.
Irazu, or "Nature's powder keg" as it has been called, is an irregularly sub conical active stratovolcano. At 3,432 m high, it is the highest in the country, and has a long history of eruptions and eruption cycles. They typically consist of powerful emissions of large clouds of steam, ashes and scoria, often accompanied by local or regional seismic tremors; by subterranean rumblings, which can sometimes be heard in the Central Valley and by showers of rocks, which are occasionally incandescent.
The name Irazu comes from an indigenous origin, the real word is actually "Istaru", which means "Thunder and Earthquake Mountain", but with years the name it transformed to Irazu and it is the highest volcano in Costa Rica. There have been 23 eruptions since 1723, latest was during 1963 to 1965. It sent tephra and secondary mud flows into cultivated areas, killing at least 40 people and destroying hundreds of homes and some factories.
The first historic account of an eruption dates from 1723' the last period of strong activity took place between 1963 and 1965. At present, there is continuous fumarole activity and it is believed that it could become violently active at anytime. On clear days, it is possible to see the two oceans and most of Costa Rica from the top of Irazu.
Irazu Volcano's history records that the first written information about its volcanic activity was from 1723. Diego de la Haya, who was a Spanish governor of Costa Rica and he kept recollection of an eruption from February of that same year. In his writings he explains how columns of smoke and ashes were thrown along with chunks of incandescent rocks while constant seismic activity. Ashes continued to drifting for the next two and all the people from Irazu area and all the way to San Jose began having respiratory issues, this long period of activity ended in 1966 when a rock plug solidified blocking the vent.
Irazu Volcano
There are three different life zones in spite of the fact that the flora has considerably changed because of the eruptions: Premontane Rain Forest, Montane West Forest, and Montane Rain Forest, all of them lack vegetation around the craters. Tree species within these forests include: Black Oak, Alder, White Oak, Growing Stick, Miconia, Small Cedar, and Copey. The past eruptions have created visible scorched dead tree trunks near the summit and the high elevations itself avoids the vegetation from growing to tall and wide.
Plant growth is sparse within the rim of the craters yet, there is a secondary forest with patches of primary forest. Wildlife in Irazu is very scarce; near the summit you can see the rabbits, coyotes, armadillos and porcupine as well as weasels and tiger cats. If you are into bird watching, the usual species seen in the surroundings of the Irazu Volcano are hummingbirds, woodpeckers and mountain robins.
The flora has been greatly altered due to the eruptions. Most of the park presents stunted vegetation, mainly made up of arrayan (Vaccinium consanguineum), a small bush with leathery leaves. In some small patches of primary and secondary forest, the most abundant trees are the miconia (miconia spp.), the black oak (Quercus costarricensis), the growing stick (Oreopanax xalapensis) and the mountain mangrove (Clusia odorata).
The activity of the volcano changes constantly and abruptly. In the Irazu Volcano, Costa Rica shows very strong winds, it is recommended that you dress properly: boots, thick socks, and a warm jacket, sunglasses and a scarf will be incredibly useful. During the rainy season the Irazu Volcano appears to get cloudy before noon, so it is better to visit it in the morning, at any time of the day the temperature is quite cold. The facilities are open everyday until 3:00 pm and there is a lovely coffee area to rest and escape a bit from the cold while sipping a sweet hot chocolate or great Costa Rica coffee.
As you can see the Irazu volcano is not just a Volcano, natural treasures and amazing history embraces every aspect of it. If you are interested in visiting this magnificent location, contact our travel advisers and request information about tours to the Irazu Volcano, directions or any other query you may have on the subject. They will gladly help you plan an unforgettable visit this beautiful Volcano.
Irazu is very poor as regards animal life. The most frequent mammals are the eastern cottontail (Sylvilagus brasilensis) and the coyote (Canis latrans). Little spotted cat (Leopardus tigrinus) has also been seen. Among the birds, there are many humming birds and volcano juncos (Junco vulcani).
The visitor center and scenic overlook at the volcano area has a small coffee shop and tables, and is open from 8:00am to 4:00pm. Visitor services include information, a park ranger station, trails, restrooms, signage, a cafeteria, parking and several natural viewpoints.
Costa Rican Volcanoes 
