geographical boundary

A geographical boundary is a defined line or zone on the Earth's surface that separates distinct political, cultural, or natural regions.

Observed surface forms (2)

• biogeographical boundary ×2
• zoogeographical boundary ×2

Instances (3)

• Antarctic Circle
• Wallace Line concept in biogeography via concept surface "biogeographical boundary"
  surface form: Wallace Line
• the Wallace Line via concept surface "biogeographical boundary"
  surface form: Wallace Line