The Darvaza Crater's Eternal Flame - Apparently.
In 1971, a team of Soviet geologists accidentally drilled into a natural gas reservoir in Darvaza, Turkmenistan, causing the ground to collapse and create a massive crater. To prevent the spread of gas, they set the crater on fire, expecting it to burn off in a few weeks. However, the fire has continued to burn for over 50 years, making it one of the world's most unusual and long-lasting natural phenomena.