Irazú Volcano
The word Irazú is likely a corruption of Iztaru, a long-ago indigenous community whose name translated as "hill of thunder." The name is apt.
Volcán Irazú, as it’s known in Spanish, is considered active, but the gases and steam that billow from fumaroles on the northwestern slope are rarely visible from the peak above the crater lookouts. The mountain's first recorded eruption took place in 1723; the most recent was a series of eruptions that lasted from 1963 to 1965. Boulders and mud rained down on the countryside, damming rivers and causing serious floods, and the volcano dumped up to 20 inches of ash on sections of the Central Valley.
When conditions are clear, you can see the chartreuse lake inside the Cráter Principal. The stark moonscape of the summit contrasts markedly with the lush vegetation of Irazú's lower slopes, home to porcupines, armadillos, coyotes, and mountain hares. Listen for the low-pitched, throaty song of the yigüirro, or clay-color thrush, Costa Rica's national bird. Its call is most pronounced just before the start of the rainy season.
Best Time to Go
Early morning, especially in the January–April dry season, affords the best views, both of the craters and the surrounding countryside. Clouds move in by late morning. Wear warm, waterproof clothing if you get here that early.
Fun Fact
Irazú has dumped a lot of ash over the centuries. The most recent eruptive period began on the day John F. Kennedy arrived in Costa Rica in 1963. The "ash storm" that ensued lasted on and off for two years.
Best Ways to Explore
Bird-Watching
The road to Irazú provides some of the best roadside birding opportunities in the country, especially on a weekday when there isn't a constant parade of cars and buses heading up to the crater. Some of the most fruitful areas are on either side of the bridges you'll pass over. Reliable bird species that inhabit these roadsides are acorn and hairy woodpeckers; the brilliant flame-throated warbler; buzzing around blossoms, the fiery-throated green violetear; and (aptly named) volcano hummingbirds. Once past the main entrance, there are also plenty of opportunities to stop and bird-watch roadside. Look for volcano juncos on the ground and slaty flowerpiercers visiting flowering shrubs.
Hiking
Even before you get to the main entrance, check out the park's Prusia Sector, which has hiking trails that pass through majestic oak and pine forests and picnic areas. They're popular with Tico families on weekends, so if you want the woods to yourself, come on a weekday. Trails in the park are well marked; avoid heading down any paths marked with "paso restringido" (passage restricted) signs.
Volcanic Tips
A paved road leads all the way to the summit, where a small coffee shop sells hot beverages, and a persistent pair of coatis cruise the picnic tables for handouts. (Please resist the urge to feed them!) The road to the top climbs past vegetable fields, pastures, and native oak forests. You pass through the villages of Potrero Cerrado and San Juan de Chicuá before reaching the summit's bleak but beautiful main crater.
Top Reasons to Go
Easy to Get to
Irazú's proximity to San José and the entire eastern Central Valley makes it an easy half-day or day trip. Public transportation from the capital, frequently a cumbersome option to most of the country's national parks, is straightforward.
The View
How many places in the world let you peer directly into the crater of an active volcano? Costa Rica offers you two: here at Irazú and at Poás Volcano. Poás's steaming cauldron is spookier, but Irazú's crater lake with colors that change according to the light is nonetheless impressive.
More Views
"On a clear day, you can see forever," goes the old song from the musical of the same name. Irazú is one of the few places in Costa Rica that lets you glimpse both the Pacific and Atlantic (Caribbean) oceans at once. "Clear" is the key term here: clouds frequently obscure the view. Early morning gives you your best shot.
