Peirce Mill is a historic gristmill located in Rock Creek Park, Washington, D.C. Built in the early 19th century, it was used to grind grain into flour. The mill is named after its original owner, Isaac Peirce, who operated it until the mid-1800s. Today, it serves as a reminder of the area's agricultural past. The mill features a waterwheel powered by Rock Creek, which was essential for its operation. Visitors can explore the mill and learn about the milling process, as well as the history of the surrounding park. It is a popular site for educational programs and community events.