1.

Plas Tan-y-bwlch, Maentwrog, Gwynedd is a country house with an arched gatehouse and mock portcullis, now used as the Snowdonia National Park Study Centre. The house belonged to the Oakley family, who owned three of the Blaenau Ffestiniog quarries - Holland's, The Welsh Slate Company and Gloddfa Canol (Gwyn & Williams 1996). The terraced gardens (NPRN 28688) were laid out in the nineteenth century.

The house was greatly enlarged in the second half of the nineteenth century, but the main block incorporates a mid-eighteenth-century house. This had an imposing three storey frontage and a rear wing also of three stories. The timbers dated by this study were all re-used as window lintels in the rear wing of the eighteenth-century house. They probably derive from an earlier structure on the site associated with Robert ap Ievan ap Iorwerth, who died circa 1568. Tree ring dating commissioned by Snowdonia National Park Authority has dated parts of the buildings as; East wing (re-used timbers) Felling date ranges: 1525-55; 1536-61, Floor beam 1516, Cill beam 1535, Floor joist (1503).

Source: Gwyn. D & Williams. M (1996) `A Guide to the Industrial Archaeology of North-West Wales’. Association for Industrial Archaeology.

R.F. Suggett, RCAHMW, July 2007 (edited 21 November 2011)

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2.

Plas Tan y Bwlch is a country house, now the Snowdonia National Park Study Centre. It set in extensive gardens, though which the Ffestiniog Railway (NPRN 34660) runs and overlooks the Dwyryd river and the slate quays (NPRN 409346). Once the home of a Welsh landed family, it became the property of William Oakeley on his marriage to Margaret Griffith in 1789. William Oakeley was from a Staffordshire family, and his brother Charles was Governor of Madras. William Oakeley was a noted improving landlord, and developed the estate considerably, leasing out his slate quarries in Ffestiniog.

Plas Tan y Bwlch and its gardens reflect investment by William Oakeley’s heirs in the second half of the nineteenth century; the house was greatly enlarged in a Victorian idiom, and the present gardens were laid out. They form a conspicuous and picturesque location, and offer outstandingly beautiful views across the valley, including the former slate-shipping points on the Dwyryd river (NPRN 409346).

As the Snowdonia National Park Study Centre, Plas Tan y Bwlch now offers regular courses on the history and archaeology of the slate industry, its settlements and transport systems, as well as on local and regional natural and cultural heritage.

Statement of Significance:

Plas Tan y Bwlch and gardens were the home of the Oakeley family, owners of several of the major Ffestiniog slate quarries as well as of much of the land between Ffestiniog and the slate-harbour of Porthmadog. The house and the gardens and their immediate environment, refashioned in a Picturesque manner by William Oakeley and his heirs, reflect re-investment of the family’s wealth from their colonial role in India, and their commitment to developing their Welsh estates in the ‘improving’ manner. As the Snowdonia National Park Study Centre, it has become a focus for archaeological and historical study of the slate industry of north-west Wales.

This site is part of the Slate Landscape of Northwest Wales World Heritage Site, Component Part 5: Ffestiniog: its slate mines and quarries, slate town and railway to Porthmadog. Inscribed July 2020. 

Sources: 

Louise Barker & Dr David Gwyn, March 2018. Slate Landscapes of North-West Wales World Heritage Bid Statements of Significance. (Unpublished Report: Project 401b for Gwynedd Archaeological Trust) 
Tirwedd Llechi Gogledd Orllewin Cymru / The Slate Landscape of Northwest Wales. Nomination as a World heritage Site (Nomination Document, January 2020) 
Wales Slate World Heritage Site https://www.llechi.cymru/

Hannah Genders Boyd, RCAHMW, Februaru 2022 

Site Record