CHAPTER 1 What Is a Tunnel 4 CHAPTER 2 Building Tunnels 8 CHAPTER 3 Types of Tunnels 14 ACTIVITIES TOOLS Try This 22 Glossary 23 Index 24 To Learn More 24
What Is a tUNNEL What’s that up ahead A tunnel A tunnel is a passage that goes through or under roads mountains rivers and oceans
Early Greeks and Romans built mines to dig up gold They also built tunnels called aqueducts These tunnels carried fresh water to cities
