The mouth of Hell

In 1962, a little fire in Centralia (Pennsylvania) migrated into an exposed vein of anthracite coal under the town. The flames on the surface were successfully extinguished, but the coal continued to burn underground for many years, so that in 1984 the fire was completely out of control and the city had to be evacuated.
Nowadays, Centralia is an abandoned and ghostly place. The fire still burns beneath the town and there is enough coal to feed the fire for up to 250 years.