Masaya Volcano National Park, National park in Masaya Department, Nicaragua

Masaya Volcano National Park is a protected nature reserve in Nicaragua's Pacific region featuring the Santiago Crater as its main landmark. The crater sits between the Nindiri and Masaya volcanoes and continuously releases sulfur dioxide gas from its depths.

The oval caldera, 11.2 by 6 km, formed when two volcanoes—a shield volcano to the east and a composite one to the west—collapsed and merged. The Nindirí crater collapsed in the 1670 eruption, and the last lava flow at Masaya occurred in 1772. The park was designated Nicaragua's second national park in 1979.

Chorotega communities of Nindirí and Masaya offered sacrifices of maidens and children to a sorceress goddess in Nindirí crater, as their chief told chronicler Gonzalo Fernández de Oviedo in 1529. That year the Mercedarian friar Francisco de Bobadilla planted a cross on the summit to exorcise the devil he believed lived in the "mouth of hell". Chocoyo parakeets still nest in the inner crater walls.

Visitors can explore the park through organized day and night tours, each offering different perspectives depending on the time of visit. It's advisable to wear comfortable shoes and prepare for changing conditions, as the ground is uneven and the air can feel heavy due to gas emissions.

The park was designated Nicaragua's second national park in 1979, covering 5,400 hectares. Its dry tropical forest shelters coyotes, skunks, raccoons and opossums at night, while iguanas, monkeys, deer, rabbits and parrots appear by day; the parrots nest in the sulphur-laden crater walls without apparent harm.