High Wire Daredevil
Heinz Zak has devoted years to perfecting the art of high lining - a sport that involves balancing on a thin rope stretched between two points, usually high over ground or water.
High lining requires nerves even more steely than tight-rope walking because you have to walk along a loosely anchored rope instead of a rigid cable.
Heinz generally uses a harness, but he has also walked across stretches of the Zugspitze - the highest mountain in Germany at almost 3,000 metres - without using any safety equipment.
After discovering the sport in the early eighties, Heinz spent years travelling the world in search of the best walks.
The 51 year old says he doesn't do it for the adrenaline rush but as a form of meditation and a way to experience living in the moment.
His son Martin often travels with him and takes the amazing photos of his father walking.
Lucy Ash spoke to Heinz and began by asking him what it takes to walk thousands of feet above the ground.