Rincon de la Vieja, the largest volcano in the country's northwest, comprises a remote volcanic complex in the Guanacaste Range. At least nine eruptive vents are located within a 15-kilometer-wide caldera. The twin cone of 1,916 meter Santa Maria volcano, the highest peak of the Rincon complex, features an incactive crater 500 meters across. The last major eruption occurred about 3,500 years ago. All subsequent eruptions, including numerous historical events dating back to the 16th century, have occurred in the montain's lake-filled active crater.