Canada's Mount Thor has the greatest purely vertical drop of any cliff on Earth

On Baffin Island in the Canadian Arctic, Mount Thor's west face drops about 1,250 metres and overhangs at an average angle of 105 degrees, 15 degrees past vertical. That makes it the cliff face with the greatest purely vertical drop on Earth, carved by glaciers between roughly 18,000 and 1,500 years ago. Climbers didn't complete the first ascent of the face until 1985, after 33 days on the wall.

— Wikipedia contributors, Mount Thor — Baffin Island, Nunavut, Canada