Poás Volcano – Our Restless Sentinel

Poás Volcano is one of Costa Rica’s most famous tourist attractions. Its crater ranks amongst the world’s largest and is known for its stunning, emerald-colored, bubbling sulfuric lake. The Poás Volcano National Park is a must-visit destination, offering breathtaking views, unique geological features and many options.

The Sleeper Awakens

…and 2025 has become the year of Poás. The volcano shows ongoing unrest and has erupted multiple times. It does not appear finished. On April 23, gas and ash blasted from the crater and reached 4,500 meters—nearly 15,000 feet. The Costa Rican National Emergency Commission (CNE) responded by issuing a RED ALERT for the Poás Volcano National Park area. Local and international news outlets continue to report updates on the volcano’s activity. This article will remain unchanged after publication. Please follow official sources like CNE for the latest developments.

The Towering Threat

Poás Volcano sits just 30 kilometers from downtown San José and lies even closer to Costa Rica’s main international airport. Its proximity makes it a constant threat to the capital and the 3 million residents living in the Greater San José Area—nearly 60% of the country’s population. But Poás is not alone. Several other volcanoes, both active and dormant, surround the city. Some, like Irazú, stand even closer and have caused major damage in past eruptions. This volcanic ring places San José in a zone of persistent geological risk.

THE 2025 UNREST

Since early 2025, Poás Volcano has shown elevated unrest. Gas and ash eruptions, earthquakes, and steam explosions have scattered debris in all directions. In early March, the crater released a plume that rose 400 meters above the rim. Authorities raised the alert level and closed the National Park to protect visitors.

On March 11, the park reopened with strict limits. Only 56 visitors could enter at a time. Officials closed hiking trails and shortened access times. Everyone visiting the crater rim received helmets for safety. These measures aimed to reduce risk while allowing limited public access.

Activity at Poás Volcano intensified on March 18. In just 24 hours, over 200 earthquakes shook the area. The crater released nearly 700 tons of sulfur dioxide, and Laguna Caliente began to vanish. On March 28, eruptions hurled rocks up to 150 meters from the crater. Gas and ash rose 200 meters into the air. Officials closed the National Park once again, and it remains shut as of this writing.

April 21 and 23 marked the most explosive days yet. Ash clouds soared to 4,500 meters, blanketing nearby areas and triggering a Red Alert from Costa Rica’s National Emergency Commission (CNE). Towns and villages near Poás were warned to prepare for further eruptions, gas exposure, and possible lahars.

As of April 27, the situation remains unstable. Poás Volcano National Park is closed indefinitely. Officials have not announced a reopening date, and the volcano continues to emit ash and gas at hazardous levels. For now, the mountain holds its breath—and so do we.

OUR RESTLESS VOLCANOES

Costa Rica packs a volcanic punch for such a small country. It hosts nine volcanoes considered “active”—meaning they are erupting or showing signs of unrest. These include Poás, Irazú, Rincón de la Vieja, and Turrialba. Others, like Arenal, Barva, Miravalles, and Tenorio, are labeled “dormant.” They haven’t erupted recently but still hold the potential to do so.

Then there are the “extinct” volcanoes—Tortuguero, Pelado, Chopo, and Tilarán. These have lost their magma sources and won’t erupt again. Still, many continue to radiate heat and host hot springs or fumaroles. For a country barely the size of West Virginia, that’s an impressive geological lineup. Costa Rica’s volcanoes shape its landscapes, ecosystems, and even its tourism identity.

THE BEAUTY OF POÁS VOLCANO NATIONAL PARK

Poás Volcano stands as one of Costa Rica’s most iconic natural treasures. Its dramatic crater, scenic trails, crater lakes, and sweeping views make it a must-see destination. At nearly 2,700 meters (8,900 feet), the mountain offers cool, refreshing air—a welcome break from the tropical humidity below.

Laguna Botos

Laguna Botos rests inside an extinct crater near the summit. This nearly perfect circle spans 370 meters across and reaches depths of up to 9 meters. The lake formed nearly 8,000 years ago after the crater’s last eruption. Rainfall, groundwater, and possibly hydrothermal fluids feed its waters, which drain into Río Ángel. Lush cloud forests wrap around the lake, enhancing its serene green surface with a vibrant natural frame.

Forests & Trails

The slopes of Poás Volcano, beyond the crater’s harsh gases and heat, flourish with Montane and Cloud Forests. Rich volcanic soil nourishes dense vegetation, while high elevation brings steady mist that cools and hydrates the landscape. This combination creates a rare and vibrant biome. Several trails weave through the forest, offering visitors a chance to explore its lush canopy, hidden wildlife, and shifting layers of fog. Each path reveals a different mood of the mountain—quiet, mysterious, and deeply alive.

The Crater

The Poás crater is truly breathtaking. It spans 1,320 meters (4,330 feet) across—nearly a full mile—and plunges 320 meters (1,050 feet) deep. The crater’s rugged walls steam and shimmer with streaks of white, black, gray, brown, yellow, and rusty red. These colors speak to the raw, volcanic forces that shaped this ancient site.

Green ridges encircle the crater, often vanishing behind thick clouds of rising steam. Sulfuric air drifts on the wind, adding a sharp scent to the cool mountain atmosphere. Standing at the rim feels like peering into Earth’s living core.

Laguna Caliente

Laguna Caliente is the undeniable centerpiece of Poás Volcano. This crater lake shifts in color, temperature, and pH with dramatic flair. Sometimes it expands, other times it vanishes from view entirely. Its waters hold the title of most acidic lake on Earth, with pH levels that can drop to zero—matching the corrosive power of battery acid.

A layer of liquid sulfur coats the lakebed, adding to its surreal and dangerous beauty. Temperatures swing wildly, from cool and misty to boiling and violent. Laguna Caliente spans roughly 300 meters across and reaches depths of about 30 meters, though both measurements change with volcanic activity.

The Poás Volcano National Park includes a number of trails, some short and some many miles in length. The trails meander through the volcanic landscape and explore the crater, Cloud Forests, lakes and formations that dot the National Park.

ACCESS, PARKING & TRAILS

Tickets need to be purchased in advance from the SINAC (Sistema Nacional de Áreas de Conservación) website – you will need to provide some information and choose the day and time of your visit. Visitors not in possession of a pre-purchased ticket will not be allowed to enter the Park. Current Park information can be found on the SINAC website linked above – although it seems that the website is not updated with urgency so seek several sources for confirmation of important information like Park closures. Also book tickets a few days in advance as the SINAC website is known to frequently fall off-line (it seems to be off-line at the time of writing).

Summary

In summary (this info is current as at 27 April 2025 and will not be updated):

• For foreigners, entrance costs are $5 (children 2-12) and $15 (visitors 13 years old +)
• Local Costa Ricans pay 500 Colones ($1) and 1000 Colones ($2) respectively
• Parking fees are 1000 Colones ($2) for motorcycles 2000 Colones ($4) for light vehicles
• The carpark is a short walk from the crater – 600 meters or 2000 feet. It is a prepared & wide path that is wheelchair accessible
• The Botos Lagoon Circuit is 3.4 km or 2.1 miles long, taking views of the main crater, the Botos Lagoon, lush vegetation and landscape panoramas. It is a part of the main access trail between the carpark and the main crater
• Use Waze or other map app to get directions to the National Park. There is also bus access from Alajuela – but only on Saturdays, Sundays and Holidays
• The Poás Volcano National Park is currently CLOSED indefinitely due to ongoing volcanic unrest. 

ERUPTION EFFECT ON TOURISM & LOCAL COMMUNITIES

The 2017 eruptions have had a long & devastating impact on tourism and surrounding communities – unfortunately it looks like this year’s volcanic unrest has the potential to be equally destructive.

The April 2017 Events

On April 9, 2017, officials placed restrictions on Poás Volcano visits due to rising toxic gas emissions from the summit crater. Just three days later, an explosion forced the park’s closure and triggered a 2.5-kilometer safety zone around the crater. Authorities evacuated some nearby residents as a precaution.

On April 14, two eruptions launched ash and vapor over three kilometers into the sky. More explosions followed on April 16, shaking the region with earthquakes. Laguna Caliente vanished during this period, swallowed by the volcano’s violent activity.

A major blast on April 22 hurled red-hot rocks from the crater, damaging buildings and infrastructure. In response, President Luis Guillermo Solís visited affected towns to show solidarity. Business owners shared how the park’s closure devastated local tourism. Solís released a bilingual video urging travelers to support nearby shops, restaurants, and community businesses during the crisis.

Ongoing Unrest

The emergency stretched well into 2018. Rockfalls, landslides, earthquakes, ashfall, and flying debris continued to threaten nearby communities and damage infrastructure. Water pipes cracked, concrete foundations shifted, and fences collapsed under the strain. The National Park finally reopened in September—nearly 18 months after the April 2017 eruptions.

Local communities endured more than physical damage. Tourism, their economic lifeline, vanished almost overnight. Hotels, tour operators, restaurants, cafés, pubs, and souvenir shops shut their doors. With no visitors, many businesses couldn’t survive. The region faced not just geological upheaval, but a deep economic wound that took years to heal.

SIGNIFICANT HISTORICAL ACTIVITY

• Poás has erupted 40 times since 1828.
• 2024-2025: Heightened volcanic activity since late 2024, including the most recent eruptions on April 21-23, 2025, has led to closures and potential economic impacts on tourism.
• A 2017 eruption caused the park to be closed for about 18 months, leading to economic losses for local businesses.
• In January 2009 Poás was near the epicenter of a 6.1-magnitude earthquake that killed at least forty people and affected the Central valley area including San Jose.
• On May 17, 1953, an eruption occurred that started a cycle and lasted until 1956.
• Between 8 October 1914 to 15 May 1915, a significant eruptions produced extensive and far-reaching ashfalls.
• A 1910 eruption was a significant event characterized by a large mushroom-shaped cloud of ash and steam reaching heights of 8 km above the summit.

COSTA RICA’S VOLCANO ALERT LEVELS & RESOURCES

Red Alert: This is the highest level, indicating a major volcanic eruption and the highest risk to people and property. The Poás Volcano National Park is under a Red Alert as at 27 April 2025.
Orange Alert: This alert level indicates a moderate to high risk due to ashfall and gas exposure, typically affecting areas near the volcano.
Yellow Alert: This level signals increased caution and vigilance, with areas under yellow alert experiencing intermittent ashfall and volatile gas concentrations.
Green Alert: This is a precautionary warning indicating that heightened volcanic activity is being closely observed, but not necessarily an immediate threat.

A few official resources, presented below, can be consulted to learn about the alert levels and verify volcano and surrounding area alert level status. Please note that these, although official, can experience delays with presenting up-to-date information:

• Costa Rican National Emergency Commission (most up-to-date resource) CNE

• Volcanological and Seismological Observatory of Costa Rica (provides delayed notifications) OVSICORI
• National System of Conservation Areas (very slow to update) SINAC

A MUST-SEE ATTRACTION (WHEN AVAILABLE)…

It’s not only about the steaming crater – Lagunas Caliente & Botos are themselves seen as major attractions worthy of their own Wikipedia pages. The cool & misty Cloud Forests and the spectacular high elevation views over the surrounding landscape are icing on the cake. All of these sights & experiences are wrapped in one neat little package just a short day-trip away from San Jose.

Imagine living in a place where majestic, towering volcanos add a touch of surrealism to the lush, jungle surrounds. With their cloud-forest slopes, stunning crater lakes, panoramic vistas and hellish craters, the volcanoes are definitely worth a visit! This can be your life, and we can turn your dreams into reality much faster and easier than you think! To browse properties available in the South Pacific area of Costa Rica, see the RE/MAX WE SELL PARADISE  listings here.

cover image c/o Mariordo, wikicommons.