Poás Volcano: Costa Rica’s Fiery Crown Jewel
Poás Volcano isn’t just another mountain—it’s one of Costa Rica’s most photogenic and dangerous natural attractions. Rising 2,708 meters above sea level in the Central Valley, this active stratovolcano boasts one of the largest open craters on Earth. Visitors come for the cinematic views but often leave awestruck by the sheer intensity of nature’s design.
In 2024 and 2025, Poás has demanded attention not only for its surreal scenery but also for a dramatic series of eruptions and seismic activity. The volcano’s behavior has shifted from passive bubbling to powerful ash plumes and steam bursts, transforming it into a live demonstration of geologic unrest.
The Acid Lake: A Toxic Jewel in the Crater
Poás’s main attraction is its eerie, electric-blue crater lake—a highly acidic pool that’s as mesmerizing as it is deadly. Formed by the accumulation of rainwater mixed with volcanic gases, the lake is one of the most acidic natural bodies of water on Earth, often registering a pH below 1.
The surreal color is caused by high concentrations of sulfur, iron, and other minerals dissolved by the intense heat and chemical activity beneath. Steam constantly rises from its surface, especially in the early mornings, and during periods of heightened activity, visitors can hear it hiss like a giant kettle.
This lake has disappeared and refilled multiple times due to eruptive changes. In April 2024, it dried up completely—an ominous sign. Its absence triggered a series of gas releases and explosive phreatic eruptions, signaling deep instability within the volcano’s plumbing system.
2024–2025 Activity: Poás Awakens Again
The volcano entered a new chapter of unrest starting in late 2023. Here’s a summary of major events from 2024 and 2025:
- January 26, 2024 – Steam Eruption:
A massive burst of steam rose over 700 meters above the crater, alerting authorities and nearby communities. - April 2024 – Crater Lake Vanishes:
The complete drying of the acid lake exposed bubbling mud pots and intense fumarolic activity. Gas emissions increased dramatically. - March 2025 – Orange Alert Issued:
Volcanologists at OVSICORI recorded rising seismic activity, prompting a nationwide Orange Alert due to the heightened risk of eruption. - April 21, 2025 – Major Eruption:
A powerful phreatic eruption launched ash and steam 4 kilometers into the sky—the strongest event at Poás since 2017. Ashfall affected roads, towns, and prompted temporary closures of the national park.
Today, the volcano remains highly active, with constant gas emissions, seismic tremors, and intermittent ash events. Access to the park is tightly controlled, and visitor times are shortened for safety.
A National Park Guarded by Protocol and Science
Poás Volcano National Park isn’t just another hiking destination—it’s one of the most tightly regulated parks in Costa Rica. Thanks to the volcano’s volatility, safety measures are updated frequently and enforced strictly by park staff and scientists from OVSICORI and SINAC.
Visitor Protocols:
- Timed Entry (20 Minutes):
Visitors are only allowed near the crater for brief, timed sessions. This helps reduce exposure to toxic gases and ensures crowd control in case of sudden activity. - Mandatory Safety Gear:
Hard hats are required for all visitors due to potential rockfall and pressure explosions. They are provided on site. - Advance Booking Required:
Due to limited entry slots, all visitors must pre-register online. Walk-ins are not permitted when alert levels are high. - Real-Time Monitoring:
The park can be closed with no notice if seismic sensors detect spikes. Officials use drones, satellite feeds, and gas detectors to assess conditions hourly.
These measures ensure that you can safely enjoy the dramatic views—while staying one step ahead of the volcano’s mood swings.
The Botos Lagoon Trail: Peace Just a Hike Away
Though the crater may be intense, just a short walk through the forest takes you to a serene and much older part of the volcano’s story: Laguna Botos.
This emerald-green lake sits inside an extinct crater, surrounded by dense cloud forest. It’s a 45-minute loop trail that offers a complete sensory shift from the sulfurous crater rim.
What you’ll find along the trail:
- Epiphytes and Orchids:
These air-loving plants grow on trees, drawing moisture from the mist and rain. - Hummingbirds and Tanagers:
Dozens of bird species dart through the trees, many found only in Costa Rica’s highland forests. - Cool, Moist Air:
The trail’s cloud forest ecosystem is humid but refreshing, offering a break from the dry volcanic wind near the summit.
It’s the perfect complement to the intensity of Poás’s active crater—an area of calm and balance in a land constantly in motion.
Local Life Beneath the Volcano
The towns of Grecia, Alajuela, Poasito, and Fraijanes have adapted to life alongside the volcano. Agriculture thrives here, thanks to the fertile volcanic soil. Coffee plantations, strawberry fields, and lush gardens dominate the landscape.
Yet, the community is always aware of the potential danger. Schools run annual evacuation drills. Many homes are stocked with emergency kits. Tourism, while essential, now comes with greater coordination between guides, rangers, and local businesses to keep everyone safe and informed.
A Living Laboratory for Global Science
Poás isn’t just Costa Rica’s geological jewel—it’s a world-class research site. Scientists from around the globe study it for insights into volcanic gas chemistry, geothermal energy, and eruption forecasting.
The volcano is equipped with:
- Gas Emission Analyzers:
These measure sulfur dioxide, carbon dioxide, and hydrogen chloride levels, which can indicate magma movement. - Thermal Cameras and GPS Sensors:
These track temperature fluctuations and ground deformation to detect changes in pressure beneath the surface. - Collaboration with Universities:
Both local and international students visit the site for hands-on research, making it one of the most accessible volcanoes for scientific education.
How to Visit Poás Volcano Safely in 2025
With ongoing eruptions and safety alerts, planning ahead is essential. Here’s how to make the most of your visit:
- Check the Status First:
Visit the official SINAC and OVSICORI websites for live updates on closures, alerts, and gas levels. - Arrive Early:
Cloud cover usually sets in after 10 AM, and mornings offer the best visibility. - Dress in Layers:
Temperatures vary quickly from the hot crater rim to the cool forest trails. - Follow the Rules:
Stay within marked trails, wear your helmet, and don’t linger beyond your time slot. - Travel with a Guide:
Guides not only enhance the experience but are trained in emergency evacuation procedures and volcano science.
Why Poás Is More Relevant—and Thrilling—Than Ever
In a world where many natural wonders are static, Poás remains alive, volatile, and deeply captivating. It is one of the few places on Earth where you can witness the Earth’s inner energy just a few feet away—yet still return to a calm hotel room that evening.
For those who respect nature and love raw, powerful experiences, Poás is a must. But come prepared, come informed, and come with a sense of awe. Because this volcano is not just a destination—it’s a reminder that the Earth is never truly at rest.
