ELI5: Explain Like I'm 5

Lava cave

A lava cave is a dark, underground tunnel that was formed from hot, melted rock (called lava) that flowed out of a volcano a long, long time ago.

Picture this - you know how when you make a sandcastle on the beach and pour water over it, the sand gets all mushy and creates little tunnels? That's kind of what happens with lava when it flows down a volcano. As it moves, it starts to cool on the outside, but stays hot and gooey on the inside. This creates a hard, crusty layer on top of the lava flow, while the molten rock continues to move and flow underneath.

Over time, the lava starts to cool and harden even more, leaving behind a tunnel or a cave. Inside this cave, you might find weird-looking rocks, drips of lava that have formed cool shapes, and even pools of water (which can take hundreds or thousands of years to form!).

Exploring a lava cave is a little bit like going on a really cool treasure hunt. You get to see all kinds of fascinating sights that were formed by volcanoes, and imagine what it might have been like for lava to flow all around you! But it's also super important to be careful, because caves can be dark and slippery, and you don't want to get lost or hurt.