This is the cruel moment an elephant is forced to walk across a metal tightrope to form a tourist attraction in Thailand.The fully-grown animals are being trained to teeter across reinforced ropes in front of hordes of tourists at the controversial Safari World on the outskirts of Bangkok.Trainers make the elephants climb on to a raised platform before they make their way gingerly across using their tails to balance.When they reach the other side, the animals then turn around ponderously before balancing on just three legs and walking back.