Springs and their Secrets

There are places where water mysteriously springs from the earth to give life. These vital sources hide in their bowels complex, grandiose and unsuspected aquatic networks. "Into the secret of sources" takes us to the Philippines, Florida and Namibia for an astonishing underground exploration. Thanks to intrepid geologists and biologists, worlds made up of chasms, vast galleries and caves sheltering a unique fauna, will reveal their secrets to us.