What is a UNESCO natural heritage?

The United Nations Educational, Scientific and Cultural Organization (UNESCO) is a unit of the United Nations that has taken up the task of protecting the natural wonders of the world. World heritage is classified into cultural and natural heritage. Cultural heritage signifies important cultural sites, such as the pyramids in Egypt; natural heritage signifies natural wonders such as the Great Barrier Reef in Australia. Along with the places of extraordinary beauty and natural wonder that are worthy of protection, the UNESCO World Heritage list also includes those areas that tell us about the evolution of life on the Earth, such as Wadi al-Hitan(valley of whales) in Egypt, where many fossilized skeletons of whales were found.