Irazú, Costa Rica's highest volcano and one of its most active, rises  to 3432 m immediately east of the capital city of San José. The  massive volcano covers an area of 500 sq km and is vegetated to  within a few hundred meters of its broad flat-topped summit crater  complex. At least 10 satellitic cones are located on the southern flank  of Irazú. No lava flows have been identified from Irazú since the  eruption of the massive Cervantes lava flows from south-flank vents  about 14,000 years ago, and all known Holocene eruptions have  been explosive. The focus of eruptions at the summit crater complex  has migrated to the west towards the historically active crater, which  contains a small lake of variable size and color. Although eruptions  may have occurred around the time of the Spanish conquest, the first  well-documented historical eruption occurred in 1723, and frequent explosive eruptions have occurred since.  Ashfall from the last major eruption of Irazú during 1963-65 caused significant disruption to San José and  surrounding areas. Irazu Location: 9.979° N, 83.852° W Elevation: 3.432 m Photo: Rolf Cosar Photo: Rolf Cosar HOME