Volcán de Agua, also known locally as Hunahpú, is a largely unstudied volcano in Guatemala, situated less than 10 km south of the city of Antigua Guatemala, between the active volcanoes of Pacaya and Fuego. The population centres of Ciudad Vieja, Santa María de Jesús, Amatitlán and Palín also lie within 15 km of Agua’s summit, with a total population of approximately 550,000. There is little published work on either its erupti...