A watermill is a building with machinery that uses the power of flowing water to grind grain into flour or power other equipment. The key part is a large wheel with paddles or buckets around its edge. When a stream or river flows past, the moving water pushes against these paddles, making the wheel turn. That spinning motion drives gears and millstones inside the building.

For thousands of years, watermills were vital to communities. Before electricity, grinding grain by hand was exhausting work. A watermill could grind in an hour what might take a person all day. Millers became important figures in their towns, and people would bring sacks of wheat or corn to be ground into flour for bread.

The same principle powered other machines too. Some watermills sawed lumber, others hammered iron, and some even powered early factories. You can still see old watermills in many places, often beautiful stone buildings beside streams, with their great wheels either restored and turning or sitting silent as monuments to an ingenious technology that shaped communities for centuries.