The current Plas Newydd was built in the late eighteenth century, but it incorporates an earlier medieval house, one of those of the Griffiths of Penrhyn. The house was transformed into the current structure under the initiative of Henry, 9th Baron Paget, who used James Wyatt, having employed him at Beaudesert in 1771?2. The process took thirty years and others, including John Cooper of Beaumaris were involved. It was Cooper who carried out much of the first phase of the re-development, using the Moelfre limestone that was subsequently used throughout the building. The earlier gothic style was much reduced, particularly at the southern end where three close spaced bays sit to the left of the south-eastern tower. The second phase, between 1793 and 1799 was directed by James Wyatt in association with Joseph Potter of Lichfield. This work included re-fitting of the saloon and ante-rooms (probably by Wyatt) and the Gothick Hall and the classical stair hall (probably by Potter).

The house and its grounds stands within a large landscaped park (NPRN 265416). From about 1800 anciliary buildings were moved away from the house and are now scattered about the park. These include: the stable court (NPRN 31094); home farm (NPRN 403205); walled gardens (NPRN 15826, 15828), and dairy (NPRN 31092).

Source: RCAHM Anglesey Inventory (1937), 56
Source: CADW Listed Buildings Database (5462)
Source: Haslam, Orbach and Voelcker (2009), The Buildings of Wales: Gwynedd. Pevsner Architectural Guide, page 153.

RCAHMW, October 2009