“To make a walk,” explains the sculptor Richard Long, “you are following the whole history of mankind, from the early migrations on foot from Africa that brought people all over the world.” Long himself often makes long walks around the world, stopping here and there to create sculptures along the way. He absorbs nature into classical geometries—lines and circles—channeling mountains, coastlines, grasslands, and snowscapes. His land art is often constructed from mud, stones, and earth. Featured in Leuven’s BANG festival—which celebrates the Big Bang Theory—Long’s installations reflect on existence and the void. —E.C.