The cliff is probably a natural formation, older than the cross.

In any case it was too smooth to be a natural formation.

He told me that it was a natural formation.

Although the natural formations were so popular, they presented a difficulty for Louis.

"It could not be a natural formation then, I suppose."

He sat down next to me and called my attention to what seemed to be a natural formation on the mountains towards the northeast.

Something which could not be mistaken for a natural formation or phenomenon.

To be fair, most of the Sound's limitations are inherent in its natural formation.

"Does that look like a natural formation to you?"

"Or some other natural formation that has stood the test of time."