ELI5: Explain Like I'm 5

retaining wall

A retaining wall is like a big Lego wall that grown-ups build to hold back dirt and rocks so they don't fall down. Imagine your sandbox has a hill on one side, and you want to make it flat for playing. If you just push the dirt down, it will slide back to where it was because of gravity. But if you build a wall out of Lego blocks, the dirt stays in place and you can play on the flat surface.

A retaining wall does the same thing but on a bigger scale. Sometimes grown-ups want to build a house or a road or a park on a hill. They don't want the dirt and rocks to slide down and block the way or hurt people, so they use the retaining wall to keep the hill in place.

The wall can be made out of different materials like stones, bricks, or cement blocks. The blocks are stacked on top of each other like Lego, but they are attached with special glue or metal bars called rebar to make them strong. This way, the wall can hold back tons of dirt and rocks without falling down.

There are different types of retaining walls depending on how tall and how steep the hill is. Some walls are straight, while others have curves or steps to make them look nice. Some walls have plants or grass growing on them to make them blend in with nature.

So, next time you see a big wall holding back a hill, you can think of it as a giant Lego wall keeping everything in its place.