Fires that have burned underground for decades

This is something I've been aware of, but many are not, it's getting some high profile coverage in Time Magazine - Deep Underground, Miles of Hidden Wildfires Rage. I tend to believe the fact that these fires are often not reported and there are more of them than we know. Which means underneath us, the fires continue and could become huge issues for people and our planet.

It's also happening in Ohio - for over 122 years one coal fire has burned. More information that can be found here and how angry mine workers in New Straitsville, Ohio set the fire in 1884 during a labor dispute never thinking it would remain burning.