Visitors will be able to explore some of North Wales’ most remarkable historic houses, castles, gardens and rarely opened buildings free of charge this September.
National Trust Cymru and Cadw are among hundreds of organisations taking part in Open Doors 2026, the annual celebration of Wales’ heritage and culture.
Throughout September, participating venues will offer free admission, guided tours, activities and behind-the-scenes access, providing opportunities to discover the people, events and landscapes that have shaped the nation.
Fifteen National Trust Cymru places across Wales will take part, including Penrhyn Castle near Bangor, Plas Newydd on Anglesey, Bodnant Garden and Tŷ Mawr Wybrnant.
Meanwhile, Cadw’s programme includes free events at Harlech and Denbigh castles, Ruthin Gaol and the ancient Barclodiad y Gawres burial chamber on Anglesey.
Dr Ffion Reynolds, Cadw’s Senior Heritage Events and Arts Manager, said: “Open Doors is a fantastic opportunity for people to explore the extraordinary heritage on their doorstep and discover places they may have never visited before.
“Whether you’re interested in castles, archaeology, industry, religion, literature or local history, there is something for everyone.
“By opening these places free of charge, we’re helping more people connect with the stories, people and landscapes that have shaped Wales.”
National Trust Cymru events in North Wales
Tŷ Mawr Wybrnant, Penmachno – 5 and 6 September, noon–4pm
Nestled in the Wybrnant Valley, Tŷ Mawr Wybrnant was the birthplace of Bishop William Morgan, the first person to translate the entire Bible into Welsh – an achievement credited with helping to secure the language’s survival.
The property will open on both days, with talks about its history, garden and cultural significance.
Find out more about Tŷ Mawr Wybrnant
Plas Newydd House and Garden, Anglesey – 12 and 13 September, 9.30am–5pm
This Grade I-listed house stands on the banks of the Menai Strait, with dramatic views towards the mountains of Eryri.
Visitors can explore 40 acres of gardens and 129 acres of woodland and parkland free of charge. Art materials will be available around the garden, while special artist packs will encourage visitors to get creative.
Find out more about Plas Newydd
Bodnant Garden, Conwy – 12 and 13 September, 9.30am–5pm
Established in 1874 by Victorian entrepreneur Henry Pochin, the Grade I-listed Bodnant Garden features Italianate terraces, formal flowerbeds, ponds, woodland, meadows and riverside dells.
September visitors can expect displays of dahlias, rudbeckias and heleniums, along with late roses and sweeping banks of hydrangeas beside the river.
Find out more about Bodnant Garden
Penrhyn Castle and Garden, Bangor – 19 and 20 September, 10am–5pm
Penrhyn Castle’s vast rooms, neo-Norman architecture and opulent furnishings are intertwined with histories of slavery, colonialism and the North Wales slate industry.
The castle and grounds will be free to visit throughout the weekend. Quarrymen from the National Slate Museum will give slate-splitting demonstrations, while a Victorian kitchen baking demonstration will take place on Sunday.
Find out more about Penrhyn Castle and Garden
Erddig Hall and Garden, Wrexham – 19 September, 10am–5pm
Erddig tells the stories of the Yorke family and the generations of servants who lived and worked on the estate.
Visitors can explore its preserved rooms, collection of servants’ portraits, restored 18th-century garden and extensive landscaped parkland. September is also a particularly colourful time along Erddig’s 220-metre herbaceous border.
Chirk Castle and Garden, Wrexham – 19 September, 10am–5pm
Chirk is the last Welsh castle built during the reign of Edward I that remains lived in today.
Its medieval towers and dungeons sit alongside elegant state rooms, award-winning gardens and terraces overlooking the Cheshire and Shropshire plains. Visitors can also explore walking routes across the 480-acre estate.
Find out more about Chirk Castle
Plas yn Rhiw and Sarn y Plas, Llŷn Peninsula – 26 and 27 September, 10.30am–4.30pm
Overlooking Cardigan Bay, Plas yn Rhiw is a 17th-century manor house with Georgian additions, an ornamental garden and extensive coastal views.
The gardens at Plas yn Rhiw and nearby Sarn y Plas, once home to poet R S Thomas and artist Mildred Eldridge, will be free to enter.
A free guided walk will leave Sarn y Plas at 1.30pm on both days and finish at the Plas yn Rhiw tearoom. The route passes Fron Deg, a traditional smallholding cottage dating from the 1870s. Booking is essential for the walk.
Find out more about Plas yn Rhiw
Other Open Doors highlights in North Wales
Ruthin Gaol – 12 September, 12.30pm–3pm
Visitors can go behind the scenes at North East Wales Archives, housed within the Grade II-listed former Victorian prison.
Special tours will reveal how centuries of records, some dating back to the 12th century, are preserved within its secure archive stores. Family activities will also be available.
Barclodiad y Gawres, Anglesey – 13 and 27 September, 11am–4pm
One of Wales’ most important Neolithic monuments will offer rare public access to its passage tomb and decorated stones.
Located on the Anglesey coast, the burial chamber provides a remarkable insight into life more than 4,000 years ago.
Denbigh Castle – 19 and 20 September, 10am–5pm
Visitors can explore this imposing medieval fortress, built as part of Edward I’s ring of castles across North Wales.
Free guided tours, talks, workshops and family activities will highlight features including its triple-towered gatehouse, curtain walls and panoramic views.
Dolbelydr, Denbighshire – 19 and 20 September, 10am–4pm
Rarely open to visitors, Dolbelydr is a restored 16th-century gentry house believed to be where Henry Salesbury wrote the first grammar of the Welsh language.
Visitors will be able to explore its historic interior and learn about the conservation of its surviving Elizabethan features.
Harlech Castle – 26 and 27 September, 11am–4pm
Free guided tours led by Siân Roberts will explore the events, people and legends associated with one of Wales’ best-known medieval fortresses.
The castle forms part of a UNESCO World Heritage Site and occupies a dramatic position overlooking the coast and the mountains of Eryri.
Open Doors is organised and funded by Cadw as Wales’ contribution to the European Heritage Days initiative. Some events and guided tours require advance booking, despite admission being free.
The complete programme and booking information are available on the Cadw Open Doors website.
Photos: (1) Drone view of the neo-Norman Penrhyn Castle in autumn at Penrhyn Castle and Garden, Gwynedd. (2) Visitors exploring Plas Newydd House and Garden, Anglesey. Photos © National Trust Wales.
