Steep hills and the river defined the east side of the battlefield, and lower ridges the west.

From this point on, the river had well defined banks all the way to the Suir.

This river defines the boundary between Mullion and the neighbouring parish of Gunwalloe.

These rivers define the main geographical subdivisions of the region:

The river Pasvikelva runs through the valley (giving it the name) and the river defines part of the Norway-Russia border.

During the colonial era the river defined the boundary between the Kibuye and Gisenyi Prefectures.

Occasional deviations would be allowed, but in general the river would define the journey.

The river defined the town, in 1857, 38 mills had the right to use the waters of the rivers to power themselves.

The river defines the border between Israel and Jordan.

The river once defined part of the boundary between Dumfriesshire to the east and Kirkcudbrightshire to the west.