How Did Roman Roads Last for Two Millennia?

Imagine building a tower out of Legos. If you just stack them dry, they might wobble and fall over when it rains. Roman roads were like those Lego towers, but with a special glue.

The Romans didn't just dump rocks on the ground. They built their roads in layers, kind of like an onion. First, they put down big flat stones at the bottom to hold everything up. Then came smaller stones and sand. Finally, they added the top layer made of heavy stone blocks.

The best part was the dust they used called pozzolana. It comes from volcanoes in Italy. When you mix this dust with water and lime (a powder made from burnt rocks), it gets really strong. In fact, it gets stronger over time! That is why some Roman roads are still standing today while modern streets crack after only a few years.