Lonely Planet review
Just 37km north of Alajuela by a winding and scenic road is the most heavily trafficked national park in Costa Rica. And for those who want to peer into an active volcano – without the hardship of hiking one – it’s ideal. The centerpiece is, of course, Volcán Poás (2704m), which had its last blowout in 1953, which formed the enormous crater, measuring 1.3km across and 300m deep.
Poás offers the wonderful opportunity to watch the bubbling, steaming cauldron belch sulfurous mud and water hundreds of meters into the air. There are two other craters, as well, one of which contains a sapphire-blue lake ringed by high-altitude forest.
The main crater at Poás continues to be active to varying degrees. In fact, the park was briefly closed in May 1989 after a minor eruption sent volcanic ash spouting more than 1km into the air, and lesser activity closed the park intermittently in 1995. In recent years, however, Poás has posed no imminent threat, though scientists still monitor it closely.