It is formed by the action of wind and water on rocks over thousands of years.

VOA: special.2009.09.14

So trees are actually able to grow on rocks. They have very strong roots."

VOA: special.2010.07.13

The easiest way to get the rest of the oil out is to place heavy rocks on the crushed material.

VOA: special.2009.09.29

It includes long,thin,red and white rocks that reach high into the air like fingers on a hand.

VOA: special.2009.04.15

When the sun shines on the almost straight-sided rocks, they look like bright shining wings rising out of a mountain of green trees.

VOA: special.2009.07.20

Odell said they had just climbed one of the most difficult rocks on the northeast path.

VOA: special.2010.06.30

On either side of the path are what look like river beds of big rocks.

VOA: special.2009.07.20

And climbers sometimes have to hold on to rocks by only their fingers or toes.

VOA: special.2009.12.09

"This one is beautiful. This is one of my favorite rocks. You can see that black stuff on the outside, it's called the fusion crust.

VOA: special.2010.07.28

Police continue to confront youths armed with rocks on a weekly basis.

VOA: standard.2009.04.08