266 photos of Porous Limestone Cliffs

Reference Pack: 266 photos of Porous Limestone Cliffs by atenitsky

http://www.fotoref.com/products/porous-limestone-cliffs-1?variant=2115642982424

Limestone cliffs with a lot of small round holes it surface. It's relatively easy to climb and therefore became very popular among rock climbers.

In fact, you can see very similar surface used for climbing in different games like Tomb Raider or Uncharted.

And this is a great reference library for this type of rock formation.