The Economic Times

In 2008, Spain began filling 300-metre-deep coal mine with 547 billion litres of water; four years later, the site looked nothing like it once did

A vast open-pit coal mine in As Pontes, Spain, has been transformed into a large artificial lake. Engineers filled the enormous excavation with billions of litres of water over four years. This ambitious project created a lake, beach, and nature trails, repurposing the landscape. The former industrial site now serves as a recreational and tourism destination for the community.