The Door to Hell, Turkmenistan - Geologists accidentally found an underground cavern filled with natural gas. Actually they drilled it in Derweze in Turkmenistan in 1971. The ground beneath the drilling rig collapsed. Now there is a large hole with a diameter of about 50-100 meters. Scientists decided to set the hole on fire in order to avoid the poisonous gas to escape. Geologists had hoped the fire would go out in a few days. They were wrong. The fire has been burning ever since. This place was named The Door to Hell by the locals.