Poás Volcano
Towering north of Alajuela, the verdant Poás Volcano is covered with a quilt of farms and topped by a dark green shawl of cloud forest.
That pastoral scene disappears once you get to the 8,885-foot summit, and you gaze into the steaming, bubbling crater with smoking fumaroles and a gurgling, gray-turquoise sulfurous lake. You'll swear you're peering over the edge of a giant witches' cauldron. That basin, 2 km (1 mile) in diameter and nearly 1,000 feet deep, is thought to be the largest active volcanic crater in the world.
Poás is one of Costa Rica's five active volcanoes—it has erupted 40 times since the early 1800s—and is one of those rare places that permit you to see volcanic energy this close with minimal risk. Authorities closely monitor Poás's activity following several eruptions in March 2006, the first significant increase in activity since 1994. The most recent activity took place in late 2018 and produced clouds of smoke. Access is normally open, but park officials close the route up here when there is evidence of any activity they deem "irregular."
Best Time to Go
The peak is frequently shrouded in mist, and you might see little beyond the lip of the crater. Be patient and wait awhile, especially if some wind is blowing—the clouds can disappear quickly. Aim to get here before 10 am. The earlier you arrive, the better the visibility.
Fun Fact
Forgot your umbrella? Duck under a sombrilla de pobre (poor man's umbrella) plant. These giant leaves can grow to diameters of 3 to 5 feet.
Best Ways to Explore
Bird-Watching
Although birding can be a little frustrating here because of cloud and mist, more than 330 bird species call Poás home. One of the most comical birds you'll see in Costa Rica is usually spotted foraging in plain sight on the ground: the big-footed finch, whose oversize feet give it a clownish walk. Its cousin, the yellow-thighed finch, is easy to recognize by its bright yellow, er . . . thighs. Arrive early and bird around the gate before the park opens, and stop along the road to the visitor center wherever you see a likely birding area. In the underbrush you may find spotted wood quail or the elusive buffy-crowned wood-partridge. The trees along the road are a favorite haunt of both black-and-yellow and long-tailed silky flycatchers.
Hiking
From the summit, two trails head into the forest. The second trail, on the right just before the crater, winds through a thick mesh of shrubs and dwarf trees to the eerie but beautiful Botos Lake (Laguna Botos), which occupies an extinct crater. It takes 30 minutes to walk here and back, but you'll be huffing and puffing if you're not used to this altitude.
Volcanic Tips
A paved road leads all the way from Alajuela to Poás's summit. No one is allowed to venture into the crater or walk along its edge. Take periodic breaks from viewing: step back at least every 10 minutes, so that the sulfur fumes don't overcome you. Be sure to bring a sweater or a jacket—it can be surprisingly chilly and wet up here.
Top Reasons to Go
A+ Facilities
You're on your own in many Costa Rican national parks, most of which are lacking in facilities, but this wheelchair-accessible park is a pleasant exception, with an attractive visitor center containing exhibits, a cafeteria, gift shop, and restrooms.
Bubbles and Ash
"Up close and personal with nature" takes on a whole new meaning here. Costa Rica forms part of the Pacific Rim's so-called Ring of Fire, and a visit to the volcano's summit gives you a close-up view of a region of the earth that is still in formation.
Location, Location, Location
Poás's proximity to San José and the western Central Valley makes it an easy half-day trip.
More Than a Volcano
The park is not just about its namesake volcano. A few kilometers of hiking trails let you take in the cloud forest's flora.
