Interstate 35
The sea.
The sea.
Mississippi River
British territory surrounded the globe. there was no western boundary.
The Ohio river
The Panama Canal is in Panama, which is part of North America. However, it is between South America and the bulk of North America. The canal is not a natural border or boundary between the two continents.
The Alps mountain range forms a natural boundary between France and Italy.
The Appalachian Mountains became the western boundary of the British colonies.
Australia's natural boundry is the ocean.
Natural
the equator...... i think
Lake Victoria acts as a boundary between Tanzania, Uganda, and Kenya. Another natural boundary between these countries is the Kagera River.