Full Report for Listed Buildings

Summary Description of a Listed Buildings

Reference Number
Building Number
Date of Designation
Date of Amendment
Name of Property
Plas Tan-y-Bwlch including attached terrace walls to east and west  


Unitary Authority
Street Side
In an elevated location, set within private grounds above the NW side of the A487(T) on the W approach to the village of Maentwrog.  


Broad Class

The estate of Tan-y-bwlch has a long history: the earliest documentary record is dated 1541, and the name 'Tan-y-bwlch' is first recorded in the 1660s. Ieuan ap Iorwerth ap Adda is recognised as the founder of the estate, with a lineage traced back to the Princes of Gwynedd in the late C11 and early C12. The estate passed down through Evan and Griffiths families until an heiress married into the Oakeley family in the later C18. Under the Oakeleys, enriched by ownership of slate quarries, the estate became a by-word for improvement, and much of the landscape and buildings on the estate, including the Plas itself, owe their characer to successive generations of Oakeleys. The first Plas is thought to have been sited elsewhere, perhaps on the site of the Oakeley Arms, and the earliest house on the present site is that built (though perhaps not completed) by Robert Griffith in 1748. Traces of this eighteenth century house are perhaps discernible in the fabric of the present house, but its architectural character is that of the later nineteenth century rebuilding, under the patronage of William Edward Oakeley. The estate was sold in 1962 and acquired by Snowdonia National Park in 1968.  

C18-C19 mansion in castellated gothic style. Faced with local stone, with sandstone dressings and granite quoins; slate roofs behind embattled parapets; tall stone stacks, with paired shafts, moulded drip-stones and cappings. The house is planned to take advantage of its lofty site, with entrance in the east side elevation, leaving the long south elevation for reception rooms. Service rooms (kitchen etc) at the rear. Main south-facing range apparently entirely of late C19 date, is 3 storeyed, with principal elevation facing south: this has large tower-like block to the right with large full-height canted bay, then a symmetrical 3-window range with advanced stepped-gabled central bay. Mullioned and transomed windows throughout, of 3 and 4 lights, with hood-moulds forming continuous string courses in the right-hand range. SE wing is earlier in character, and perhaps represents the surviving core of the C18 house. It forms the entrance range: a 3-storeyed, 3-window range, with entrance at its left: heavy projecting porch with buttresses, embattled parapet and moulded arch-way. Windows are 12-pane hornless sashes (9-pane in attic storey), with string courses stepped to form their hood-moulds. Attached to the right side of this wing is a later C19 grand gateway leading to the rear service yard: this has arched entrance with faux portcullis, and embattled parapet tepped over a central gable. West of the main range and set back from it is a further late C19 range: single storeyed over a basement, with embattled parapet and gable detail, mullioned and transomed windows (incuding two projecting bays). At the rear, parallel to the SE wing, lies a further wing which also seems to be part of an C18 (or early C19) building. This is also 3-storeyed, and has sash windows as before, though unornamented. Alongside it, to the rear of the tower of the main range, are paired late C19 service wings, single storeyed with steep roofs (that to east with lantern glazing). A small enclosed yard is integral with them to the west. The house is tightly integrated with its garden on its steeply sloping site, and retaining terrace walls continue the lines of the house to east and west: at the west a long length of rubble wall with raking ashlar coping curves round to the western entrance to the stable yard: the coping is surmounted by piers with ball finials, between which are lengths of ornamental iron railing.  

The internal layout owes much to the late C19 remodelling, which established a series of reception rooms running to the south of a spinal corridor, with grand staircase off to the north as well as the service accommodation. Layout of rooms remains substantially intact, with some good surviving detail including a series of fireplaces with elaborate overmantels.  

Reason for designation
Listed as a fine gentry mansion, its architectural character dominated by late C19 castellated Tudor gothic work, but incorporating elements of an earlier house, also mildly gothic in character. The house is prominently sited in a fine landscaped setting, and forms the historic centre-piece of an important estate and its landscape.  

Cadw : Full Report for Listed Buildings [ Records 1 of 1 ]