Land At Glyn Milwr Stones Houses, Blaina, Blaenau Gwent Data via plota.co.uk

From the Mining Remediation Authority, formerly the Coal Authority. The development high risk area marks recorded coal mining features at or near the surface: mine shafts and adits, shallow workings, mine gas and former opencast sites. Most planning applications there need a coal mining risk assessment; householder applications, changes of use and some minor works are exempt. Mine entry positions come from old plans and can be out by several metres, and unrecorded workings can exist anywhere in the coalfield.

Harm to a protected site is only accepted where there is no alternative and an overriding public interest.