There are no written records of the horror early humans encountered when the volcano in present-day Lake Toba, Indonesia, erupted more than 70,000 years ago. But the blast might have changed the history of our species.

Stanley Ambrose of the University of Illinois believes that the Toba eruption, which spewed up to 3,000 cubic kilometers of material, caused so much death that only about 10,000 adult humans survived, and that all modern humans descend from that tiny population.

His hypothesis hasn't been proven; however, one thing we do know is that Toba is the second-largest known eruption in history. It left behind a giant caldera that formed the largest volcanic lake in the world: Lake Toba, seen here. The largest eruption in modern times, which also occurred in Indonesia, is yet to come on this list.