Volcán de Agua (also known as Hunahpú by Maya) is a stratovolcano located in the departments of Sacatepéquez and Escuintla in Guatemala. At 3,760 m (12,340 ft), Agua Volcano towers more than 3,500 m (11,500 ft) above the Pacific coastal plain to the south and 2,000 m (6,600 ft) above the Guatemalan Highlands to the north. It dominates the local landscape except when hidden by cloud cover. The volcano is within 5 to 10 km (3.1 to 6.2 mi) of the city of Antigua Guatemala and several other large towns situated on its northern apron. These towns have a combined population of nearly 100,000. It is within about 20 km (12 mi) of Escuintla (population, c. 150,000) to the south. Coffee is grown on the volcano's lower slopes.

The local Kaqchikel people have always called the volcano Hunapú "place of flowers" or Jun Ajpu' "one hunter" (The calendar date for the sacred site; a typical method for naming sacred sites in Mayan cosmovision) in current Kaqchikel orthography. The Spanish conquistadors also called it Hunapú until a lahar from the volcano on September 10, 1541 destroyed the original capital of Guatemala (now known as Ciudad Vieja) and the city was moved to the current site of Antigua Guatemala following this disaster. Among the casualties was the governor Beatriz de la Cueva. As the lahar produced a destructive flood of water, this prompted the modern name "Volcán de Agua" meaning "Volcano of Water", in contrast to the nearby "Volcán de Fuego" or "Volcano of Fire". The Kaqchikels call Volcan de Fuego Chi Gag, which translates to "where the fire is" or Chi Q'aq' in current Kaqchikel orthography.