La Gran Sabana is a region in the Bolívar State of South-east Venezuela. The Gran Sabana sits atop the Guyana (or Guiana) Shield, one of the world's oldest geological formations. It dates back to the Pre-Cambric era, over two billion years ago. The sedimentary rock is full of gold and diamonds and mining in the area has caused severe environmental damage over the last century. Although mining is prohibited inside the park, it takes place all around its borders. The sedimentary rock of the Shield here has eroded in such a way to create huge massifs with vertical cliffs which rise out of the plains and forests into the skies.