Alex Honnold just led the first ascent of one of Earth's tallest Arctic sea cliffs—for science

“We literally went off the edge of the map to reach this wall,” Honnold said, via satellite phone from the team’s base camp, referring to the nautical maps the team had been following, which offered no details about the fjord where Ingmikortilaq is located. “It is definitely one of the biggest first ascents I’ve ever done–and one of the most stressful due to how dangerous the climbing was.”