Just how big is Ffos-y-Fran?
It is the biggest opencast coalmine in the UK - and it has caught the eye of the United Nations.
A report from the UN says there should be an independent investigation into the potential health impacts of the Ffos-y-Fran site near Merthyr Tydfil in south Wales.
It follows a long campaign by nearby residents.
The UN findings are disputed by the mine operator, which has claimed the report is biased.
Whatever the truth - one fact is beyond dispute - Ffos-y-Fran is big - really big.
- From the section Wales