Chi-mon or Chi mon is the Ninja discipline of geography.

The ninja of medieval Japan would spend many days in classrooms learning the geography of Japan and memorizing its major rivers and their tributaries. In addition, ninja would learn geology, zoology, and entomology in order to enable them to determine their location, based on which plants and animals surrounded them.

Other skills include familiarizing themselves with the major imports and exports of surrounding provinces: knowledge which could be used for sabotage.