Guarda Streamingcommunity. The Cores are a very special family. Christian was world champion in bouldering, Stella was Italian champion, and just over a year ago they became parents of twins, Lara and Ania. They live in a valley not far from Savona, Italy, but their story is inextricably linked to the woods overlooking Varazze. With other climbers from the area, they have sought, found and cleaned rocks to climb with more and more extreme difficulty, bringing to light a climbing spot now famous all over the world. In particular, they have discovered a rock and a problem thought to be the toughest in the world, which was named Gioia by Christian, the first to climb it.