CPAT logo
Cymraeg / English
Back Home
Projects index

Geophysical Survey on The Great Lawn at Powis Castle, Welshpool


Geophysics in action - photo 2667-0012 © CPAT

A magnetic gradiometer survey was carried out by the Clwyd-Powys Archaeological Trust on the Great Lawn, a grassed area below the terraces to the south-east of the castle, on behalf of the National Trust. The lawn was previously the site of a Dutch-style water garden, which is believed to have been completed by 1705 and is partially depicted on an engraving of around 1750. The garden appears to have comprised four parterres aligned north-west/south-east, the central two of which were occupied by ponds of rectangular shape with semi-circular ends of smaller diameter than the pond width. Both ponds had a central statue surrounded by four small features that may have acted as fountains, although this is not certain. Statues were also placed centrally in the two outer parterres. In addition to the features depicted in this engraving, it is known that a cascade ran down the slope facing the castle and emptied into a further pool, described as a ‘noble Bason’ by John Bridgeman in 1705. In the later part of the 18th century the water garden fell out of favour because of its outmoded style, and this, coupled with a number of other factors relating to the running of the estate, led to it being dismantled and replaced by the Great Lawn at the beginning of the 19th-century.

The raw and interpeted geophysics data

photo 2667-0018 © CPAT A first glimpse of the geophysics results for CPAT and National Trust staff.

Three main anomalies were identified, comprising traces of the three ponds mentioned above, these being the main features of the 18th-century water-garden. Although faint, the ponds were visible in the results and the geophysics gives a measurement for each of approximately 21m north-west/south-east by 13m. The pond at the base of the cascade was also evident, measuring some 20m north-east/south-west, although its other dimension could not be determined as the south-eastern part of the pond is masked by later features, namely a path and the main drainage culvert for this part of the gardens. No evidence of the locations of any of the statuary was found, although that would not be expected with this type of survey. It was, however, possible to locate their approximate former positions by combining the geophysics results with the 18th-century sources.

Various linear features were also revealed by the survey, but most of these were land drains placed in the later part of the 20th century. Two possible drains or water supplies were identified which could link the pond at the base of the cascade with the two ponds in the parterres, although the magnetic response was fairly faint and this theory cannot be confirmed. Likewise, a linear feature or features running along the south-east side of the lawn may represent traces of the early 18th-century parterres, or perhaps a drainage feature earlier than the modern drain which runs alongside the path.


Eighteenth century engraving held by Powys County Archives A mid eighteenth century engraving of Powis Castle, showing some of the features that now lie hidden beneath The Great Lawn. Reproduced by kind permission of Powys County Archives


Privacy and cookies