Plas Machynlleth was the Welsh residence of the Marquesses of Londonderry, situated in the market town of Machynlleth in Powys (formerly Montgomeryshire), Wales. It was brought into the family by the marriage of George Henry Robert Charles William Vane-Tempest, Viscount Seaham and future Earl Vane and 5th Marquess of Londonderry, to Mary Cornelia Edwards, whose father Sir John Edwards had extended and renamed the house.
The house was the family home of the 5th Marquess. His eldest son left Machynlleth on succeeding to the Marquessate, but his youngest son, Lord Herbert Vane-Tempest, remained resident at the Plas until he was killed in the Abermule train collision on 26 January 1921.
The building of the house stretches over 200 years, with the oldest parts dating back to the 17th century while the main entrance front was added in 1853. The house was called Greenfields for many years. It was later re-named after the town.
The 7th Marquess of Londonderry decided to give the mansion and its estate to the town, and the house was used for council offices. In 1995, after a £3 million refurbishment, funded by Montgomeryshire District Council and the European Union, the building became the ‘Celtica’ heritage centre. The attraction was successful for a number of years attracting tourist and educational visits and conferences. However, it was taken over by the new unitary authority, Powys County Council, and with little investment by the Council and declining visitor numbers the Council decided to close the centre in 2006, citing a loss of £1.1 million between 1998 and its closure.[1] The Plas is now used as a community and meetings venue.
Other residences of the Marquesses of Londonderry.