Sado (Japan) (AFP) – Under a split-top mountain on the Japanese island of Sado lies a network of centuries-old gold and silver mines that have sparked a new diplomatic row with South Korea. Japan believes that lengthy history and the artisanal mining techniques used there merit recognition on UNESCO’s World Heritage List. But in Seoul, the focus is on what isn’t mentioned in the bid: the use of conscripted Korean labour during the Second World War, when Japan occupied the Korean peninsula.