French daredevil Alain Robert has taken on his biggest challenge yet: The infamous skyscraper-climber successfully ascended the United Arab Emirates’ Burj Khalifa, the world’s tallest skyscraper at 2,717 feet. Before he began the climb, Robert said he expected the task to take about seven hours, but it took just over six hours. Unlike in previous feats, he wore a rope and harness. Ominously, an ambulance and stretcher were waiting at the ground level should anything go awry.
