Climber Heinz Zac crosses a highline from Lost Arrow spire in Yosemite National Park with only a safety leash to protect him from the nearly 3,000ft (900-metre) dropPhotograph: Heinz Zak/Barcroft MediaThe vertigo-inducing view down from Lost ArrowPhotograph: Heinz Zak/Barcroft MediaHeinz's highline walks have taken him around the world to challenging locations such as Alderspach in the Czech RepublicPhotograph: Heinz Zak /Barcroft MediaThe view down to earth in MunichPhotograph: Heinz Zak/Barcroft MediaHeinz walks across to Devil's Tower in Dresden, GermanyPhotograph: Heinz Zak/Barcroft MediaHeinz serenely walks across a lake in Stubai, AustriaPhotograph: Heinz Zak/Barcroft MediaStunning views of the Matterhorn provide a backdrop to Heinz's highline walk in SwitzerlandPhotograph: Heinz Zak/Barcroft MediaWalking into the sunset in Dresden, GermanyPhotograph: Heinz Zak/Barcroft MediaHeinz performs his highline walk in Styria, AustriaPhotograph: Heinz Zak/Barcroft Media