Sand is all around us. It's the main ingredient for concrete and we use it to build our houses and city infrastructures. It's the second most exploited natural resource ahead of oil and natural gas. While it seems to be an infinite resource, only a small portion of the sand on our planet is exploitable. Beaches and rivers are being harvested with devastating impacts on the environment. With the help of geologists, engineers and nature advocates, we explain why sand is such an important part of our lives and how we can protect this valuable resource.