Why is this the answer?

The answer is map because this is a super clever riddle that makes you think about how we draw the world to understand it better. A map is a special kind of picture that shows us where everything is, even though it is just made of paper and ink. Let's look at the first part of the riddle: "I have rivers without water." On a real map, rivers are always shown with long, winding blue lines. These lines tell you exactly where the river flows, from its start all the way to the ocean. The map has the river's path, but you know there is no actual water to drink or splash in. It is a drawing to help you find your way across the land. Next, the riddle says, "Forests without trees." If you look at a map, you might see big patches of green color. Those green spots tell you that a forest or a large park is in that area. The map shows the whole space where the trees grow, but you will not see little tiny drawings of every single tree. It is a helpful symbol to show a big area of woods where many plants and animals live. Then, there are "Mountains without rocks." A map shows mountains with special curved lines or sometimes uses shaded colors to tell you how high the land is. You can see the tall, bumpy shape of a mountain range, but the map itself is flat and does not have any stones or big, hard rocks to climb. The drawing tells you the mountain is there. Finally, the riddle mentions, "Towns without houses." When you look for a city or a town on a map, you usually see a little dot or a small symbol, and the name is written right next to it. That small dot stands for the whole town where all the buildings, people, and houses are. The map is a wonderful tool that gives you a tiny picture of a great big world.