Boulder

Have you ever seen a really, really big rock? So big that you can't push it, or even roll it? That's called a boulder! It's like a giant stone that decided to stay put. If a rock is smaller, like the size of a big apple, it's called a cobble. And even smaller ones are pebbles, like the ones you skip on the water. But a boulder is a true giant of the rock world!

Boulders are like pieces that broke off from even bigger rocks or mountains a super long time ago. Imagine a huge mountain that got cracked and pieces fell off. Over many, many years, wind and rain might have smoothed their edges, making them rounder. Sometimes, they get moved by rivers or even glaciers, which are like giant rivers of ice. They can travel a long way before settling down.

Boulders are super important because they help shape the land! When they sit in a river, they can change how the water flows. Animals might use them for shelter or to climb on. And for us, they make amazing places to explore and play around. Some boulders are so big, they look like they belong in a fairy tale! They are like nature's sculptures.

How big is a boulder? Well, it has to be bigger than your head, and even bigger than a basketball! To be a real boulder, a rock needs to be wider than 25.6 centimeters, which is about the length of a ruler. Some boulders are so massive, they are bigger than a car, or even as big as a small house! They are truly impressive giants of nature.