A rapidly growing crater known as the "hellmouth" has given scientists a fascinating insight into 200,000 years of climate history.
The 300ft-deep Batagaika Crater in Siberia is expanding a rate of 30 to 100 feet each year allowing scientists to see ancient layers that once lay hidden.
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The crater, in northern Yakutia, is referred to as a "mega slump" and dubbed by locals as the "Doorway to the Underworld".
As a permafrost continues to thaw away its layers, the ground underneath becomes more exposed.
This enables researchers to see what the landscape once looked like, helping them to predict the changes yet to come.
In a new study, published in Quaternary Research , researchers analysed the sequence of permafrost deposits in the Batagaika crater, revealing a number of different environmental conditions throughout the years.
They have found remains of wood, indicating the presence of two forest beds and high amounts of pollen - which indicates the area once featured an open tundra landscape, according to researchers.
Julian Murton of the University of Sussex told the BBC that the layers provide a "continuous record of geological history, which is fairly unusual.
"That should allow us to interpret the climate and environmental history there.
"We are still working on the chronology."
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The now half-a-mile-long crater first formed in a clearing of forest land in the 1960s.
It sits near the village of Batagai, in the Verkhoyansk district.
Many villagers believe it is a 'portal to the underworld' after hearing monstrous sounds coming from it.
But scientists say they are likely to be produced by falling soil rather than creatures from the deep.