Irazú

Irazú is Costa Rica's tallest volcano at 3,436 m (11,273 ft), and on clear days both the Pacific Ocean and Caribbean Sea are visible from its summit.

The 1963 eruption began on the same day that U.S. President John F. Kennedy arrived in San José for a state visit — ash reportedly fell on the presidential motorcade.

The 1963–1965 eruption lasted approximately two years, depositing volcanic ash across the entire Central Valley and triggering lahars that killed approximately 20 people.

All known Holocene eruptions of Irazú have been explosive — no lava has flowed from the volcano in approximately 14,000 years.

The summit crater lake changes color dramatically from vivid green to turquoise to rust-red, depending on chemical and mineral conditions, making it one of Costa Rica's most photographed natural features.

Irazú's volcanic massif covers approximately 500 km², making it one of the largest volcanic edifices in Central America by area.

At least 10 parasitic cinder cones on the south flank indicate that the volcanic system extends well beyond the main summit complex.

The Diego de la Haya Crater is named after the Spanish colonial governor who first documented an eruption of Irazú in 1723.

Approximately 2 million people live in the San José–Cartago metropolitan corridor within Irazú's broader ashfall hazard zone.

Irazú Volcano National Park, established in 1955, is one of the most visited national parks in Costa Rica thanks to the paved road access to the summit.