Sand is all around us. It is the main ingredient of concrete and we use it to build our homes and urban infrastructures. It is in fact the second most exploited natural resource ahead of oil and natural gas. If sand seems to be an infinite resource, a tiny part of the sand found on our planet is exploitable. To obtain this resource, some beaches and rivers are destroyed and the effect on the environment is devastating. With the help of geologists, engineers and conservationists, we explain why sand is such an important part of our lives and how to protect this precious resource.