And soon or late, they must be out of sight of those natural walls.

Easily defended, too, what with the rocks making a natural wall on one side.

"That high slope behind the building is a natural defensive wall."

There were rocks here to form a natural wall, and I backed the car against that.

It is a natural or artificial wall, usually earthen and often parallels the course of a river.

Then the gardens here, and a kind of natural wall with steps cut into it.

He skirted a dull natural wall and entered yet another valley.

It was closed on all sides by high and seemingly natural walls of stone.

Today, the lake also poses a threat because its natural wall is weakening.

Just one trail leads to the top of a natural wall where is possible to see the spinner dolphins.