Archaeologist cuts 200 years off age of 'Tudor' garden

One of the most unusual and important gardens in Wales has opened for the summer with a shadow being cast over its architectural authenticity.

Three and a half million pounds - including £750,000 from the Heritage Lottery Fund - has been spent to transform the gardens, at Aberglasney in Carmarthenshire, from a jungle of Japanese knotweed, yew, box and ivy roots into an attraction that drew in 31,000 people last year, the first its eight acres were open. This year's first visitors admired magnolias and hellebores yesterday, apparently uninterested in the academic tensions.

Aberglasney is reputedly Britain's only surviving Tudor cloister garden but in an article in the journal Post Medieval Archaeology, Stephen Briggs, an archaeologist with the Royal Commission on the Ancient and Historical Monuments of Wales, has said the estate is not what it claims to be.

Dr Briggs says that, rather than being 400 years old, Aberglasney was built during the Agricultural Revolution of the late 18th century, as a range of cowsheds around a muck yard and vegetable patch. Dr Briggs says there was no known functional garden on the site before the 1770s and no decorative garden before 1800. The earliest reference to a cloister comes from an artist in 1783, who speaks of a terrace on stone arches and most definitely does not describe them as old. Itgets worse for Aberglasney. Dr Briggs writes: "Between 1770 and 1830, in gentry and minor gentry circles, meat and milk production were of less consequence to the improving farmer than was muck. Cattle husbandry actually focused on collecting and spreading cow dung."

Williams Wilkins, Aberglasney's project director, says that a farmyard would never have been built so close to the house on the windward side while Dr Briggs' evidence that an unusual yew tunnel, with ornamental gardens, were only built in the 19th century is built around his faulty examination of a watercolour, which he uses as evidence.

The Briggs article is "distressing," said Mr Wilkins, because "some people may feel it adds to the debate".

Thomas Lloyd, author of The Lost Houses of Wales, said that work undertaken since Dr Briggs' study dated the courtyard to 1600. He said: "Whatever it is, there's nothing quite like it and it does not fit any other building type."