SCIENCE | FACTS | BEYOND | HISTORY | on Instagram: "It looks simple: just a hole in the ground with a second vent. But it’s ingenious survival engineering. The vertical hole holds the fire, while the side vent supplies oxygen. This creates a strong, concentrated flame with minimal smoke. Fuel burns efficiently, conserving wood — perfect when resources are scarce. Heat is directed upward, keeping the fire low-profile. This reduces visibility to others, making it safer in survival scenarios. It’s