Supervolcano Toba caused the near extinction of the human species around 74,000 years ago. Its explosion ejected such a quantity of ash and sulfur gas that they blocked the sunlight and made life on earth impossible: plants and animals died and the air became toxic and difficult to breathe. From that day, Lake Toba on the island of Sumatra remains the largest crater lake in the world. But how did humans survive after that terrible catastrophe? It’s believed that the eruption likely created areas called refugia, where humans could survive harsh conditions. Coastal regions were especially important, as shellfish were less affected by the eruption than mainland plants and animals, providing a nutritious source of food for humans before hunting became an option again.