Compelling evidence of a massive ancient structure has surfaced in Ireland, where archaeologists working in the country’s Baltinglass hillfort landscape have discovered one of the largest settlements ever identified in the region.
The discovery of a massive enclosure at Brusselstown Ring may represent the most extensive prehistoric nucleated settlement ever identified in Ireland or Britain, according to new research that appeared in the journal Antiquity.
Drawing on data from several recent surveys and test excavations, archaeologists report the discovery of hundreds of roundhouse platforms clustered within the remains of a monumental hillfort. The findings, they say, point to an unprecedented level of population density and social organization among the site’s builders during the late Bronze Age.
A Prehistoric Settlement of an Unprecedented Scale
Located in County Wicklow, Brusselstown Ring comprises a large area spanning more than 40 hectares, with portions that extend outward toward a larger contour fort that extends to nearly three times this size.
“The Baltinglass hillfort cluster in County Wicklow stands out as one of the most complex prehistoric landscapes in Ireland, sometimes referred to as ‘Ireland’s Hillfort Capital’ due to its exceptional concentration and diversity of monuments,” the study’s authors write.
Spread out across more than a dozen hilltop enclosures along the southwestern Wicklow Mountains, archaeologists have already discovered seven major fortifications and other features in the area, which reveal ongoing use and construction efforts that ran from the early Neolithic up until the Bronze Age.
In the past, surveys conducted in the area had already identified as many as 300 possible sites that would have served as temporary shelters. Now, drawing on recent analysis of aerial imagery of the landscape, more than 600 minute topographical anomalies were revealed, which the archaeological team says is consistent with prehistoric roundhouse platform construction of the period.
Of these features, just under 100 appear within the inner enclosure, while the remaining 500 or so exist between the inner and outer ramparts.
Hillforts of this size—particularly those extending across multiple summits—are exceptionally rare not only in Ireland and Britain, but even among the great oppida of continental Europe. If the discovery is confirmed to be what archaeologists now believe it represents, it will mark the largest known prehistoric settlement ever found in the Atlantic Archipelago, vastly outsizing past roundhouse concentrations at sites that include Turlough Hill in County Clare, as well as the Mullaghfarna site in County Sligo, each of which contains as many as 150 dwellings but lacks enclosure features.
A Massive Hillfort is Revealed
Although two decades of work have already been conducted at the site, a number of questions have remained about the function and chronology of the structures it houses.
In the recent archaeological work, detailed by Dirk Brandherm, Cherie Edwards, Linda Boutoille, and James O’Driscoll in their Antiquity study, the team decided to target a series of test excavation sites from 2024, focusing on the roundhouse structures to investigate if there were structural clues that might reflect whether they were used for social or more utilitarian purposes.
Along with evidence of prehistoric occupation that test trenches revealed, archaeologists also uncovered cobbled floors, hearth features, stake holes, and other features during follow-up excavations. While few artifacts were uncovered, this is not necessarily uncommon with excavations at hillforts in this region of Ireland.
Nonetheless, radiocarbon dating helped to fill in the missing pieces of the puzzle that artifacts might normally help to reveal. Dates from organic materials at the site helped the team determine that the primary period of habitation occurred during the Late Bronze Age between 1210 and 780 BC.
Additionally, a few features the team uncovered also point to the likely reuse of the site during the Early Iron Age, which extends its period of use up to around 750–400 BC.
Unusual Features Emerge
The research team also reinvestigated a series of unusual features that turned up during the earlier test excavation period. These included one particularly large, boat-shaped structure lined with stones, which had been discovered near one of the trench locations.
Very unlike the nearby roundhouse platforms, this unusual feature included elements such as the selection of heavier stone blocks by its builders, as well as a level interior that groundwater would have once entered from an adjacent natural stone outcrop.
These elements offered clues that led the research team to conclude this may have been an ancient Bronze Age cistern, given its similarity to others that are known from past discoveries throughout Europe. However, if this were confirmed, it would not only reveal the level of sophistication in obtaining water and other resources by the ancient inhabitants at the site, but it would also represent the first known cistern associated with an Irish hillfort.
Such a discovery would provide crucial evidence of planning and communal provisioning in the region, which would be consistent with a large, permanently inhabited settlement, as opposed to the site having served purely as a defensive refuge, a seasonal gathering site, or some other common function.
Rewriting the Prehistory of the Baltinglass Landscape
Given such discoveries, the emerging picture that the ancient discoveries at Brusselstown Ring are providing could potentially challenge many long-held assumptions about Bronze Age life in this region of Ireland.
Rather than the scattered farms and small dwellings archaeological work from the past has suggested, the new findings point to the presence of a densely populated community—one that would have organized at a scale previously undocumented in this part of the British Isles.
While additional work will be required to confirm the findings, the promising discovery of what may be a large cistern alongside the existing roundhouse remnants is helping archaeologists establish an entirely new picture of what this ancient settlement might have looked like and how it functioned.
Ultimately, further investigations may help confirm that Brusselstown Ring was not simply a monumental hillfort, but a thriving prehistoric hub for the ancient people of the region, a discovery that would fundamentally reshape our understanding of Bronze Age Ireland and the lives of its inhabitants.
The team’s research paper, titled “Brusselstown Ring: a nucleated settlement agglomeration in prehistoric Ireland,” was published in the journal Antiquity in November, 2025.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.