Okay, let's imagine you are going to drive to your grandma's house, but you don't know exactly where she lives. If your mom shows you a picture of a big red barn on the way and says "when you see this barn, turn left and drive straight for a while," then that big red barn is a landmark. It's a special thing that helps you know where you are and where you need to go. Just like that big red barn, there are lots of other things in the world that are landmarks, like tall buildings, famous statues, or even mountains. They help people know where they are and where they want to go, and they can be really helpful for finding your way around a new place.