Longest-burning fires

The longest-burning fires in the world are burning coal seams, which smouldes underground at very slow burn rates, spreading around just 1 mm per minute. They occur worldwide – particularly in China, the USA and India. One of the oldest examples discovered to date occurs beneath Mount Wingen (aka "The Burning Mountain") in New South Wales, Australia. It is believed to have started around 6,000 years ago when lightning struck the coal seam where it reached the Earth's surface. Today, the fire is now burning around 30 m (100 ft) underground, as it has slowly eaten away at the seam.

Until 1866, it was believed that Mount Wingen was a volcano.