Masaya is the most active volcano in Nicaragua. It is actually made up of two volcanoes; Masaya and Nindiri, with a total of five craters. The Spanish first described the volcano in 1524. Since then, Masaya has erupted at least 19 times. From 1965 to 1979 Masaya contained an active lava lake. The last reported eruption event at Volcan de Masaya was in 2003, when a plume reportedly shot ~4.6 km into the air. The eruption in 4550 B.C. was one of the largest on Earth in the last 10,000 years.