Medieval nuns may return to haunt a developer by putting a halt to a proposed wind farm.
Banks Renewables wants to build five 115-metre turbines near Hamsterley Forest.
The company has already been told its wildlife survey work is not up to scratch and unless more is done, the project is likely to be refused by Durham County Council.
Banks is now in talks with wildlife experts to persuade them they are wrong. But the company now faces further opposition – this time from archaeologists.
Northern Archaeological Associates Limited said there are remains of a medieval convent in the proposed site, which is “likely to be of at least regional importance”.
Archaeologist Mary Fraser said nothing is known of the convent’s history or size.
She said planners should consider whether the impact of the wind farm on the historic remains would be too great.