A historic Cardiff mansion that has featured in several major television productions is opening one of its most rarely seen spaces to the public this March.
Insole Court, a Grade II listed Victorian mansion in the Cardiff suburb of Llandaff, will offer visitors the chance to explore its tower during National Lottery Open Week. The special access is available to National Lottery players and tourists as part of the nationwide celebration taking place from 7 to 15 March 2026.
Often described as one of Cardiff’s hidden gems, the mansion has served as a filming location for several well known productions. Multiple BBC One programmes have filmed there, including Doctor Who, The Trick, Decline & Fall and the crime drama Death Valley, alongside Sky One’s A Discovery of Witches. The building is also currently appearing in the BBC One and HBO drama Industry.
During Open Week, visitors will be able to climb the mansion’s Victorian tower, which is rarely accessible to the public. While the mansion and its gardens are already open to visitors free of charge, the tower offers a unique perspective of the historic building and the surrounding city.
The striking exterior of Insole Court features detailed stone carvings, including gargoyles and grotesques positioned high on the building’s elevations. Ongoing renovation work has recently revealed intricate details that have spent more than 150 years out of view from ground level.
Inside the mansion, visitors can explore several historic features, including a fireplace in the foyer inlaid with Derbyshire Blue John and Connemara Marble. The fireplace also contains a unique wartime artefact. During the Second World War, when the building served as an Air Raid Precautions headquarters, a policeman named Harold Ellis sketched portraits of Hitler, Churchill, Stalin and Uncle Sam directly onto the fireback. The drawings have been preserved and remain visible today.
The location manager behind A Discovery of Witches once described the property as “a very grand mansion… dark and brooding.”
Insole Court’s history is closely linked to the coal industry that once powered Cardiff’s growth. Construction of the mansion began in 1856 by James Harvey Insole. That same year, 114 men and boys lost their lives in the Cymmer Colliery disaster in the Rhondda Valley, a mine owned by the Insole family and one of the worst mining disasters in Welsh history.
Today, that history is recognised with a commemoration in the gardens. In 2015, forty pupils and teachers walked seventeen miles from the former pit site to Insole Court in a remembrance event known as Glo-Aur, meaning gold-coal.
After the decline of the coal industry, the mansion fell into disrepair and was closed on health and safety grounds in 2006. However, a long running campaign by local residents helped secure its future.
Local supporters formed the Friends of Insole Court in 1988 to oppose a proposed sale of the building. Their campaign lasted nearly three decades and eventually led to the formation of the Insole Court Trust and a full Community Asset Transfer from Cardiff Council, completed in 2016.
National Lottery funding played a major role in restoring the building. Since 2008, the Friends of Insole Court and the Insole Court Trust have received more than £3 million across eight grants from The National Lottery Heritage Fund, The National Lottery Community Fund and the Arts Council of Wales.
Lloyd Glanville, CEO, Insole Court Trust, says:
“National Lottery Open Week is our chance to say thank you to every person who has ever bought a National Lottery ticket. Without that support, the restoration of this building simply would not have been possible. We are excited to open the tower and give supporters a rare chance to experience the views that would have been just as impressive 150 years ago.”
National Lottery Open Week is now in its ninth year and offers special access, free entry and discounted tickets at venues across the UK. This year’s theme highlights hidden gems and lesser known attractions funded by the National Lottery.
Andrew White, Director of Wales at The National Lottery Heritage Fund and Chair of the Wales National Lottery Forum, says:
“Places like Insole Court really show why National Lottery Open Week matters here in Wales. Local people spent decades fighting to save this building, and National Lottery players helped bring it back to life. Thanks to your support, its tower is now open to the public — a very rare opportunity available during National Lottery Open Week. I’d encourage everyone to use the week to get out and explore the remarkable places right on their doorstep that they may never have discovered otherwise.”
This year’s National Lottery Open Week ambassador is Welsh actress Joanna Page, who is encouraging people to explore attractions across Wales.
Joanna Page says:
“The best days out are always the ones you don’t see coming. For one week only, hundreds of amazing places across the UK throw open their doors — from big names to hidden gems, all made possible because of National Lottery funding. I’m so excited to be part of National Lottery Open Week this year. There really is something for everyone, so get involved.”
Across Wales, dozens of venues are taking part, including behind the scenes tours at the Ffestiniog and Welsh Highland Railways engineering works in Gwynedd, free entry at Hay Castle in Powys, two for one entry at Gwrych Castle in Conwy, access tours at Maesteg Town Hall in Bridgend, guided walks at RSPB Newport Wetlands and free film previews of Amélie at independent cinemas including Theatr Clwyd in Flintshire and Theatr Gwaun in Pembrokeshire.
Beyond the tower tours, visitors can explore the ground floor rooms of Insole Court and its gardens, which have been open to the public since 1946 and are home to eight Champion Trees. Guided mansion tours are also available, while the Potting Shed Café serves locally sourced seasonal food and Butler’s Books operates from the site.
Tower Tours run exclusively during National Lottery Open Week, 13–15 March
Tower Tour tickets cost £5, or £2 for visitors presenting a qualifying National Lottery ticket or scratchcard. Booking is required via the Insole Court website.
