Glenmaroon’s ghosts: How urban explorers keep a Guinness legacy alive

Glenmaroon House, a Dublin estate with a rich history and ties to the Guinness family, has lived many lives. Now rediscovered by curious visitors, ‘urbexers’, and recently featured in the horror film Abigail, this intriguing property has an incredible story.

Glenmaroon House, perched on the edge of Phoenix Park in Castleknock, Dublin, holds a remarkable history.

Initially built in the mid-1800s by Gilbert Burns, a successful retail entrepreneur, the residence was initially known as Knockmaroon Lodge. The house radically changed in 1903, when Arthur Ernest Guinness, an Anglo-Irish engineer and member of the renowned brewing dynasty, acquired the house and decided to construct a new residence for himself and his wife, known today as Glenmaroon House.

People often share their work experience in this house on social media. This is the case with Paddy Osborne, who worked there as a gardener: “There were two houses, the North House, next to Phoenix Park, and the South House on the river Liffey side. The grounds were around 50 acres and had almost 50 men working on the grounds alone when the Guinness family owned it.”

Osborne recalls that the property featured remarkable innovations: “There were ‘fireplaces’ built into the walls connected with earthenware pipes. Fires would be lit to heat the wall to keep frost off the delicate plants grown there… Workers would have to get up at night to stoke the fires.”

Following Ernest Guinness’s death in 1949, Glenmaroon House was transferred to the Irish state.

It was then handed over to the Daughters of Charity, who repurposed it as a care home and girls’ school known as “Holy Angels”. Over time, additional structures were added: a dormitory in 1956 and a chapel around 1967.

In later years, it served as a care facility for individuals with intellectual disabilities before being abandoned.

The property’s role as a care facility left an indelible mark on many lives, as evidenced by Mary O’Flannagan, a retired social worker who shares on Facebook her family’s connection to the place: “My sister in law lived in the dorm there and went to school across the road in Holy Angels. She wasn’t abandoned or victimised; she had a mild disability, and, in those days, residential care was often recommended… My daughter went to St. Michael’s school, Holy Angels and was well looked after by the Daughters of Charity and lay teachers.”

The abandonment of Glenmaroon House did not mean it was forgotten. 

Urban explorers rediscovered the site years ago, highlighting Glenmaroon by sharing their experiences online.

Eight years ago, one urban explorer, who wishes to remain anonymous, visited the property and described the access point: “Someone had smashed a window, and nobody had covered it. So me and my friends saw it, and it was at a point where you could kind of climb up into it.”

Despite the building’s abandoned status, the explorer was struck by its preservation, saying: “It was in excellent condition. It was not falling apart at all. It’s almost as if people were still keeping it in good shape… There were parts that looked like a hospital to us… But what was weird was that they were different parts that looked completely different to each other. In one place, it could look like a hospital, and suddenly, it would be like a huge gallery room. It looked almost supernatural.”

Social media platforms such as Instagram and YouTube have amplified interest in Glenmaroon House.

Photos and videos shared by ‘urbexers’ have showcased unique features of the house to a global audience, sparking curiosity about its history.

However, these visits come with ethical and legal challenges.

Sites like Glenmaroon House often involve trespassing on private or restricted property, leading to legal consequences such as explorers risking fines, arrest, or legal action if caught.

The debate over preservation versus damage caused by exploration is complex. As one experienced explorer laments, “The more people who know, the more it will get messed up… People just graffiti and smash the place up… It dampens the enjoyment of those places because eventually they end up being totally destroyed.”

Evidence of this impact was already visible during early explorations: “There were a couple of smashed windows and a little bit of graffiti but mostly on the outside and not too much on the inside.”

To minimize these impacts, an ethical code for urbexers exists, summarised by the principle: “Take only photos, leave only footprints.”

Glenmaroon House’s future remained uncertain for many years despite growing public interest.

As Fiadh, a local resident told us, the estate encompasses two significant structures facing different fates. “The difference between the two houses is quite stark,” a longtime neighbourhood resident explains.

“The Holy Angels building has fallen into disrepair because there just wasn’t enough money to renovate it. Plus, such an old building would be hard to adapt to today’s disability standards.” In contrast, they note that the main house is “not abandoned at all anymore” and has been maintained in much better condition.

The area around these historic buildings has undergone significant transformation in recent years.

“Now it’s all changing around here,” observes one resident, pointing out that “even the farm that used to be owned by the Guinness family has stopped operating.” The property’s prominence in local memory remains strong, as “everyone in town knows it and can tell you the history of the place,” reflecting its significance in this evolving Dublin neighbourhood.

In 2024, Glenmaroon House served as a filming location for the horror movie Abigail, where its atmospheric interiors created the perfect backdrop for a foreboding 1920s manor. The property’s cinematic appeal extended to The Rebellion, where it was featured in several key scenes, including the theatre stairwell opening and sequences set at Dublin Castle.

As of February 2025, while the current ownership remains private, local sources are adamant about one thing: “It’s not abandoned anymore.”

This marks a new chapter in the ongoing story of this historic Dublin estate, even if its long-term future remains a subject of local interest and speculation.