Discovered this at the awesome site known as English Russia.

This is located in the Turkmenistan village of Darvaza.  From its entry on Wikipedia:

The Derweze area is rich in natural gas. While drilling in 1971 geologists accidentally found an underground cavern filled with natural gas. The ground beneath the drilling rig collapsed, leaving a large hole with a diameter of about 50-100 meters. To avoid poisonous gas discharge, it was decided to burn the gas. Locals have named the cavern The Door to Hell…. As Darvaza no longer has an airstrip, the crater’s site is too far from the capital to send a foam plane to put the blaze out.

So, yes.  This football field-wide fire has been burning bright for 38 years. Why aren’t the apocolyptic folks camped out here, waiting for Asmodeus’ rise?