The Art O'Neill Challenge, also known as the AON Challenge, the Art O'Neill Ultra or simply The Art O'Neill, is an approximately 60 kilometre Irish ultramarathon overnight endurance race that begins at Dublin Castle, at nighttime, and finishes at Glenmalure in the Wicklow Mountains the following day. The event takes place annually in the month of January, starting on a Friday night, and ends the following day.
The event recreates the Elizabethan era escape of Red Hugh O'Donnell and brothers Art and Henry O'Neill from Dublin Castle on 6 January 1592, and the subsequent journey by Art and Red Hugh to Glenmalure. Shortly after the trio were free of the castle, Henry O'Neill was separated from the pair and went his own direction, eventually returning safely to Ulster. O'Donnell and Art, however, alongside a guide sent to help them, continued south to the rural valley of Glenmalure, a rebel stronghold where they knew they would find safety. The men undertook the lengthy journey from Dublin by foot in the middle of winter wearing wholly unsuitable 16th century clothing and footwear consisting of linens and tunics. Along the journey over the mountains, Art O'Neill died of exposure, whilst O'Donnell survived, but lost both big toes to frostbite.
As of the 2026 event, the Art O'Neill Challenge (consisting of Trek, Hybrid and Run categories) is capped at a limit of 200 entrants, who are selected by a lottery process in the months leading up to the event. The 2026 event saw the introduction of a non-refundable fee to enter the lottery. Once selected, each successful applicant is required to pay a fee to secure their place. Since 2023, a shorter event named the AON Pursuit has taken place alongside the main AON Challenge on the same night, but only covers the first 25 km of the route, and is only open to runners. An additional 200 entrants compete in the AON Pursuit, bringing the total number of competitors to 400. The volunteer rescue service Dublin & Wicklow Mountain Rescue have been the organiser and sole beneficiary of the event since 2018.
The challenge has been completed by at least one runner in less than 5 hours, whereas it typically takes walkers "anywhere between twelve and seventeen hours" to complete. The event has been described by History Ireland as a "unique endeavour that combines history, hill-walking, mountain-running, élite international ultra-running and tourism".
History 1592 escape The Lord Deputy of Ireland Sir John Perrot arrested Art O'Neill and imprisoned him in Dublin Castle in 1585, it being the seat of British rule in Ireland. In December of 1585, Art O'Neill made a successful escape from the castle and "hid for a time in the Wicklow mountains, but, attempting to head north to Ulster, he was recaptured before 20 February 1586", according to the Dictionary of Irish Biography. In 1586, Art and his brother Henry O'Neill were imprisoned in Dublin Castle. Hugh Roe O'Donnell was kidnapped in late 1587 and was imprisoned in Dublin Castle's Bermingham Tower, where state prisoners were held. On 6 January 1592, coinciding with the day of the Feast of the Epiphany, the three men successfully escaped from the castle together. When the three prisoners were unshackled to eat, they took advantage of the gaolers.
In an Irish Times article by Frank McNally, it was noted that the men began their escape through the vertical toilet chute of a garderobe at the top of an unspecified tower at Dublin Castle, after which they negotiated their way through the River Poddle, which was at that point used as a sewer. McNally alludes to Red Hugh O'Donnell having been imprisoned in the "high-security" Record Tower, but makes no note of the location in which the O'Neill brothers were kept. Darren McGettigan, author of Red Hugh O'Donnell and the Nine Years War, notes that the three men escaped through a 'privy' into the castle moat.
Hugh O'Neill, Earl of Tyrone (c. 1550 – 1616) was instrumental in helping the men to effect their 1592 escape. Historian Jonathan Bardon contends that O'Neill organised the escape, and McNally notes that Tyrone probably achieved this by bribing Dublin Castle staff. Historian Hiram Morgan notes that Lord Deputy William FitzWilliam was most likely the recipient of this bribe, though this has never been conclusively proven. Prior to O'Donnell's imprisonment his family had allied with Tyrone. Tyrone aimed to release O'Donnell so O'Donnell could succeed his senile father Hugh McManus O'Donnell and provide Tyrone with much-needed military assistance. Tyrone placed so much importance on O'Donnell's escape that he was willing to allow Art and Henry, his family's enemies, to escape as well.
The men first needed to "scramble down a chute with an improvised rope" during which Art accidentally fell and injured his foot. Despite the injury, the group continued on, successfully crossing the River Dodder, and escaped beyond the city walls of what was at that point still a comparatively small city. Once clear of danger, Henry O'Neill was either separated from the other two by accident, or else split from them on purpose. According to the Annals of the Four Masters: The darkness of the night, and the hurry of their flight (from dread of pursuit), separated the eldest of them from the rest, namely, Henry O'Neill. Hugh was the greenest of them with respect to years, but not with respect to prowess. They were grieved at the separation of Henry from them; but, however, they proceeded onwards, their servant guiding them along...
On the 430th anniversary of the escape in 2022, the official Facebook account of the Art O'Neill Challenge described the escape thus: At the time of the escape Dublin was a town roughly corresponding to the present day Liberties. People lived outside the walls, within the area known as the Pale, but there was little by way of roads or byways to other towns. The Dublin and Wicklow mountains were unmapped and largely inaccessible, and were used as safe areas for Irish clans resisting English rule. Deep in the southern Wicklow Mountains one of the most secure of these areas was Glenmalure, which was the stronghold of Feagh McHugh O'Byrne, a powerful Chieftain, who carried out many raids within the Pale, and was a major thorn in the side of the Crown forces. Dublin at the time had a massive network of rivers and marshes all the way across what we know as south and west County Dublin, and river courses and fording points would have been crucial to any route from Dublin Castle to Glenmalure, particularly in the middle of winter. The River Poddle ran behind Dublin Castle, emptying into the Dubh Linn - Black Pool, which gave the town its name - nearby. This river would have been an essential navigation aid to the original escapees.
Cartographer John Speed's 1610 map of Dublin, completed less than twenty years after the escape, gives some indication of the size and limits of the city at the time.
Horses were supposed to have been provided to facilitate a faster and less tiring escape to Glenmalure, however these did not materialise, and the group were forced to continue by foot notwithstanding Art's injury. A gaoler's servant named Edward Eustace was sent to help the men, with whom they journeyed southwest through the outlying County Dublin villages (modern-day suburbs) of Harold's Cross, Kimmage, Templeogue, Firhouse, and Ballyboden before successfully crossing the boundary out of the area in which English law applied. Both Lughaidh Ó Cléirigh (O'Donnell's biographer) and the Annals of the Four Masters imply that Edward Eustace was the guide who escorted Hugh Roe from Dublin to Glenmalure. In contrast, O'Sullivan Beare implies that the guide, who was "sent by Fiach [O'Byrne]", was not Eustace. Alfred Webb claims that Turlough O'Hagan (one of Tyrone's men) was the guide who escorted Hugh Roe from Dublin to Glenmalure. but Hiram Morgan and Darren McGettigan clarify that though O'Hagan escorted O'Donnell back to Ulster, he was not the guide that escorted the prisoners to Glenmalure.
Glenmalure was at that point the stronghold of Fiach MacHugh O'Byrne, an ally of the O'Neill's, and a place in which they knew they would be given sanctuary. According to the Annals of the Four Masters, Glenmalure was considered "a secure and impregnable valley; and many prisoners who escaped from Dublin were wont to resort to that valley, for they considered themselves secure there, until they could return to their own country."
At this time Ireland, along with the rest of Europe, was in the midst of a period known as the Grindelwald Fluctuation (1560s-1630s), part of what is now known as the Little Ice Age which made the climate colder than usual. During their escape, Art and Hugh were caught in heavy rain and snow. Art was also "physically weak and malnourished from years of imprisonment", however another source claims he was "stout and heavy" during the escape. According to McGettigan, Art and Red Hugh eventually had to pause at a rock some kilometres from their ultimate destination, owing to exhaustion. Their guide (named Edward Hughes according to McGettigan), continued onwards to Glenmalure valley to fetch help from O'Byrne, who sent men back with food and beer to the location. An 1888 entry in Irish Monthly magazine summarised the scene that befell the rescuers: When aid came to them from Wicklow, "their bodies," say the ancient Annals of the Four Masters, "were covered with white-bordered shrouds of hailstones freezing round them, and no life was found in their members." Art indeed was dead, but Hugh survived...
The Dictionary of Irish Biography contends that O'Neill was not totally dead by the time help reached them, but rather that he was "extremely ill". Nonetheless, he died "soon afterwards and was buried in the Wicklow Mountains near Glenmalure". O'Donnell, on the other hand, went on to become one of the main leaders in the Nine Years' War against Tudor rule in Ireland.
A large wooden cross was erected in 1932 on a prominent point on Conavalla mountain, reputedly marking the point where "it is believed (Art O'Neill) lies buried". A commemorative plaque is also affixed to a large boulder some distance downhill of the cross, which reputedly marks the point where he died. These points are known respectively as Art's Cross and Art's Plaque. Art's Plaque is also sometimes known as Art's Grave.
EastWest Mapping, an Enniscorthy-based cartographic service that produces maps for hillwalkers, contends that the men were blocked at an area known as the 'Flags of Glanree' where they were forced, owing to exhaustion, "to rest under the shelter of a high rocky precipice". They note that: ...they should have followed up the Glanreebeg valley and gone via the Asbawn to get to Glenmalure... Instead the reasoning goes that they veered left and went up into Glanreemore, whence they hit upon the Flags and could go no further [..] It must be said though that this steep ground is not a complete barrier – they weren't trapped by a wall of rocks, they could quite easily have climbed the back of the valley and regained their route. Of course the guide may not have known this and perhaps also the men were too exhausted at this stage to retreat and regain the correct route...
Annie M. P. Smithson, an Irish novelist, summarised the escape in the Dublin Historical Record of September 1943 with the following account: