By Brady Haran BBC News Online

In the last of our five-part series looking at the precise centres of Great Britain and the home nations, we find a threat to the beautiful centre of Wales. It's cold and a light drizzle is falling across the farmland near Cwmystwyth - but Brynmor Morgan could not be happier.

The sheep farmer has just learned his property lies at the geographic centre of Wales.

"I remember my father saying our place was pretty central, but had no idea about this," he said.

The knowledge is not only a source of pride for Mr Morgan - he hopes it can be used to block the proposed construction of wind turbines in the region.

Wind turbines are planned for a nearby ridge

"Building turbines at a place like this would be a rape on the countryside.

"This area should not be spoiled... and perhaps people will think differently now that we know this place is special for another reason."

The Campaign for the Protection of Rural Wales (CPRW) is fighting plans for the 39-turbine farm at Cefn Croes, with backing from many locals.

However, the �35m project is supported by the government and environment group Friends of the Earth.

The turbines, creating the UK's biggest wind farm, would be on a ridge overlooking the exact centre of Wales.

The centre, about 2.5km (1.5 miles) from Cwmystwyth, was calculated by the nation's official mapping agency, the Ordnance Survey.

I did always feel in quite a central location

John Morgan

To be precise, the spot lies on a hillside near the boundary of Mr Morgan's farm and the adjacent Lewis farm.

A small brook, Nant Milwynd, runs nearby and the fields are rumoured to be the site of the Celts' fiercest battles, Mr Morgan said.

The Morgans have lived there for seven generations and currently farm about 1,200 sheep on 540 hectares.

Mr Morgan himself has branched out from sheep farming by starting his own consultancy business.

His recent roles have included helping find locations for the Tomb Raider sequel being filmed in Wales and starring Angelina Jolie.

John Morgan: Born at the centre of Wales

Mr Morgan's uncle, John Morgan, was born on the farm 80 years ago.

"I am surprised to find out this is the exact centre, although I did always feel in quite a central location," he said.

The co-ordinates were calculated by computer using a "centre of gravity" method.

To put it simply, it denotes the point at which a cardboard cut-out of Wales could be perfectly balanced on the tip of a pencil.

While this is not the only way to calculate the centre of an irregular-shaped object, it is the one preferred by most mapping agencies.

The islands of Wales were factored into the calculation.

The Ordnance Survey grid reference is SN 79728.22 71704.43.

Over this week, BBC News Online revealed what lay at the centre of each of the home nations.

The reports included:

• Monday: The heart of Great Britain is surrounded by peat bog.
  Click here for story

• Tuesday: Two claims for the centre of England.
  Click here for story

• Wednesday: Meg the collie roams the middle of Northern Ireland.
  Click here for story

• Thursday: The construction crew at the centre of Scotland.
  Click here for story