From Greenfields to the Plas
A mansion has stood here since the 17th century, when the house was known as Greenfields. In the 1750s it was bought by a solicitor, John Edwards, and the elegant three-storey core that survives today was built in 1765. His descendant Sir John Edwards, 1st Baronet, who died in 1850, enlarged the house into a residence fit for the leading family of the district — a country seat sitting, unusually, right on the edge of the town centre, a two-minute walk from Maengwyn Street. That closeness has shaped its whole later story: few Welsh towns have a mansion and landscaped park folded so neatly into everyday life. Today the house is known simply as Y Plas — “the mansion” — a name that says everything about how completely the town has absorbed it.
The Londonderry era
In 1846 Sir John's daughter and heiress, Mary Cornelia, married George Vane-Tempest, later 5th Marquess of Londonderry, and the Plas became the Londonderry family's Welsh seat, remaining so until 1884. The family's mark is all over Machynlleth: the town's famous clock tower was raised by public subscription in 1874 to celebrate the coming-of-age of their son, Viscount Castlereagh, the year before. The connection ended in sadness and change — Lord Herbert Vane-Tempest died in the Abermule train collision of 1921, and the estate was sold in 1931. Then, in 1948, came the gesture the town still enjoys daily: the 7th Marquess gave the mansion and its 40-acre grounds to the people of Machynlleth. The house is Grade II* listed and its gardens are Grade II registered — more of the era is told on our town history page.
Celtica, 1995–2006
The Plas had its most ambitious reinvention in the 1990s. After a £3m refurbishment, it reopened in 1995 as Celtica, a heritage centre telling the story of the Celts, and for eleven years it was one of Mid Wales's flagship visitor attractions. Celtica closed in 2006, but the investment left the mansion in good order for its next life as a community building — and it fixed the Plas in a generation of childhood memories across Wales. The episode fits a town that keeps reinventing itself, from Glyndŵr's capital to green-technology pioneer to festival town.
What Celtica cost — and what it taught
Celtica is worth dwelling on, because it is one of the more instructive heritage-tourism stories in Wales. Developed by Montgomeryshire District Council, part-funded by a European Union grant and opened by the singer Bryn Terfel, it was built for 100,000 visitors a year. It never came close: around 31,000 was the reality, and by the time it shut its losses had passed £1 million. Powys County Council, which took over the running of it in 1997, would not subsidise the gap indefinitely; a last search for £250,000 of outside investment came to nothing, and the doors closed in March 2006. The Town Council took ownership in April 2008 and made it the community centre it is now. The moral is not that the idea was silly, but that a small town cannot carry a big-ticket attraction on its own footfall. What has endured instead is low-overhead and locally run: the volunteer-staffed Parliament House, free to enter, and MOMA Machynlleth, whose exhibitions cost nothing to see.
Forty acres: the parkland today
The park is the part of the gift the town uses every day, and it is a designed landscape rather than a patch of grass. Cadw's register records around 40 acres of parkland with some four acres of formal gardens, laid out from about 1840 by Sir John Edwards and developed by the Londonderrys. Two formal drives served the house — the main one in from Maengwyn Street past Norbury Lodge, the other out to West Lodge, both lodges from around 1840 — and one survives as a path through the gardens. Oaks are planted informally through the park, with beech and sycamore along the southern boundaries; a cedar and a thujopsis were put in by royal visitors in 1896 and 1911. On the south side is a cruciform rose garden with a fountain at its centre, and behind it the walled kitchen garden of about 1830–40, its glasshouses long gone. Look for the ponds and their stone-lined dams, the ice-house, and Coed Llynlloedd woodland behind. Later years took bites out of the edges — housing, an industrial estate, sports pitches and the leisure centre all sit on former parkland — but the core is intact, and serves as the town's dog walk, picnic ground and short-cut. Our families page has more on Machynlleth with children.
Y Plas today: café, comedy and a free park
Today Y Plas belongs to the town in every sense. It is home to Machynlleth Town Council and to Caffi y Plas, and each early-May bank holiday it becomes one of the principal venues of the Machynlleth Comedy Festival, the low-key festival founded in 2010 that now draws more than 8,000 people to the town. The surrounding parkland is a free public park, open to everyone — lawns, mature trees and easy strolling right off the town centre, and one of the best picnic spots in the Dyfi Valley. Next door on Aberystwyth Road is the Bro Ddyfi Leisure Centre, with a swimming pool and gym, run by Freedom Leisure (tel 01654 703300).
Practical Information
Y Plas and its park sit immediately south-west of the town centre, a couple of minutes' walk from the clock tower — simply follow the signs from Maengwyn Street. The park is free and open to all; the café and community facilities keep their own hours, so check locally before a special trip, and expect the whole site to be given over to festival-goers on the comedy weekend. The town's Wednesday market, the Parliament House and the shops of Maengwyn Street are all within an easy stroll, making the Plas parkland the natural green finish to a day in town.
Day trips