10 world’s biggest and most amazing holes.
The one above is in Darvaza Gas Crater, Turkmenistan. In 1971, geologists discovered a massive underground deposit of natural gas on this site. Whilst excavating the hole to tap the gas, the drilling rig collapsed leaving a massive hole. To prevent poisonous gasses from escaping, the hole was allowed to burn. It continues to burn to this day and has done so without ceasing. See more here.