Masaya Volcano sits inside Nicaragua's oldest national park, just 20 kilometres from the capital city Managua. That makes it one of the most accessible active volcanoes on Earth. The main crater is called Santiago, and inside it the lava lake glows like a giant red eye — especially dramatic when you visit at night.
The volcano has a long history. People who lived here hundreds of years ago were so amazed by it that they threw offerings into the crater. Spanish explorers who arrived in the 1500s called it the 'Mouth of Hell' — they were frightened by the glowing light and the rumbling. A small cross still stands at the rim, placed there very long ago.
The gases rising from the lava are very strong, so visitors must drive through quickly with their windows closed, or wear special masks. Parakeets, amazingly, have made their nests right inside the crater walls — they zoom in and out past the rising gases without any trouble at all. Scientists find this extraordinary.
Masaya also has lava tubes — long underground tunnels made when the outer lava cooled and hardened while the hot lava inside kept flowing and drained away. Some of these tubes are big enough to walk through, and bats live in them in huge numbers.