What are lava tubes?

Lava tubes are like tunnels made by lava when it cools down and hardens.

Imagine you're eating a big bowl of hot chocolate with marshmallows on top. The hot chocolate is the lava, and the marshmallows are the soft, flowing parts of the lava. When the hot chocolate starts to cool, the marshmallows might sink or get pushed aside, leaving behind a space, kind of like a tunnel.

Now imagine that hot chocolate was inside a big container, and as it cooled, it left behind an empty tunnel. That’s what happens with lava tubes! The hot lava flows out from a volcano, and as the outside cools, it hardens into rock, but the inside stays warm and keeps flowing, like your hot chocolate still moving around in its bowl.

Eventually, the inside lava stops flowing and cools down too. What’s left is a big, empty tunnel made of rock, just like the space left behind by the marshmallows.

Sometimes these tunnels are so big you could walk through them, or even drive a car! They’re found on Earth, and even on other planets like the Moon and Mars.