Interdisciplinary thematic learning aims to guide students in applying knowledge from multiple subjects to address complex real-world problems. This paper adopts the typical water conservancy project “Qiqiao” in eastern Zhejiang as a case study in local geography. Using a problem-based learning format, it integrates knowledge from geography, science, Chinese language, history, ethics and rule of law, and other disciplines. Centered on the two themes of “protecting water veins” and “continuing cultural heritage,” the study designs an inquiry-based project and a problem chain structured around four tasks: “why was Qiqiao built,” “how did it foster culture,” “how does it convey values,” and “how can its legacy be sustained.” Through this framework, students are guided to explore the scientifi c principles, cultural value, and contemporary signifi cance of Qiqiao from perspectives such as geographical constraints, cultural symbolism, and human–environment coordination. The study provides a practical reference for interdisciplinary geography teaching and the development of local geographical resources.