Welsh Blacks will eventually move into the reconstructed byre

The byre, made from mountain boulders and a pegged slate roof, is the latest exhibit at the Museum of Welsh Life at St Fagans, near Cardiff.

Donated two years ago, it will complete the picture of the life of a Welsh quarryman's family two centuries ago.

Eventually, the tiny byre will begin its new life as a home to some of the museum's Welsh Black cattle.

The St Fagans museum has become the focus in recent years for buildings showing Wales cultural and industrial past - like the valleys' Oakdale Workmen's' Institute faithfully reconstructed there.

So the arrival of the 18th Century byre called Cae Adda marks a return to the museum's rural roots.

Cae Adda represents an extremely rare survival of a building tradition that was once common in Snowdonia John William Davies

It will be sited next to Llainfadyn, the small quarryman's cottage at the crossroads of the museum.

Although the Snowdonia cottage was donated to the museum in the 1950s, the outbuildings which would have accompanied it were not, and so the full interpretation of how tough a quarryman family's life would be was not available till now.

John Williams Davies, Director of the Museum of Welsh Life, stressed the importance of re-erecting such a small and seemingly insignificant building.

"Although we have tended to move away from re-erecting rural buildings in the last few years by moving the urban industrial Rhyd-y-car Terrace from Merthyr Tydfil and the Oakdale Workmen's Institute, it is vitally important that we fully interpret Llainfadyn which is one of our most popular exhibits.

"Cae Adda represents an extremely rare survival of a building tradition that was once common in Snowdonia."

The byre was donated by Geraint Rees Roberts of Waunfawr, Gwynedd and was dismantled and reconstructed boulder by boulder by the museum's specialist historic buildings unit.

The move south has been carefully documented

Each stone, weighing up to four tonnes, was numbered and carefully measured, and the information recorded on detailed drawings an photographs to make sure the by was re-erected accurately.

Throughout the project the museum has worked closely with the community group Antur Waunfawr which has followed the process closely.

Local children who built knee high models of the imagined original inhabitants of Cae Adda and their inhabitants were joining in the celebrations on Wednesday, along with artists Luned Rhys Parri and Catrin Williams.

The exhibition will stay open through the summer, but then the byre will provide a new home for the Welsh Blacks, taking the shed right back to its roots.