Uncovering a lost landscape: The archaeology of Llanddwyn Island

Located off the south coast of Ynys Môn (Anglesey), Llanddwyn Island was home to a small monastic community for more than 1,000 years. Now a decade of archaeological investigations have shed vivid light on this remote religious community, documenting the remains of a 12th-century church and its surrounding landscape. George Nash, Philip Dell, Leslie Dodd, Thomas Wellicome, and Carol James explain further the history and archaeology of one of Wales’ hidden island gems.


Llanddwyn Island is linked to Anglesey by a short causeway that is periodically severed by the tide, and (limited) archaeological evidence suggests that humans have made this crossing since probably the Bronze Age, if not earlier. The story becomes clearer, however, in the medieval period, when more visible material evidence reflects the establishment of a small Benedictine monastery centred on Llanddwyn Abbey, in probably the 12th century. This was based around the lore of St Dwynwen, the Welsh patron saint of lovers – although her story is rather more complex than her romantic epithet implies.

According to legend, Dwynwen was one of 24 daughters (at least 24; some sources name more than 30) of King Brychan, a 5th-century ruler who himself later became a saint. She fell in love with a young man named Maelon, but (the narrative varies) was already promised to another or chastely rejected his advances. Maelon’s response to this disappointment was to force himself on Dwynwen, after which she prayed to God to forget her love for her attacker. The Almighty went further than this, however, transforming Maelon into a lump of ice, and as a final gift, the story goes, an angel also granted Dwynwen three wishes. Her first request was that Maelon be freed from his frozen fate; she next wished that all true lovers should either gain their heart’s desire or be released from their passions; and finally, she asked that she would never marry. This last wish was achieved when Dwynwen took the veil, retiring to a reclusive religious life on Llanddwyn Island, where she died around AD 460.

Located off the south coast of Anglesey, Llanddwyn Island has a religious past dating back more than 1,000 years.

After Dwynwen’s death, the island became an important place of pilgrimage, and a church dedicated to the saint was built about 60m north of the monastic settlement, probably in the 13th century. This building was abandoned in the 18th century, and today its ruined remains represent one of the most visible reminders of the island’s religious story. The site is now a scheduled monument in the care of Cadw and, ahead of a long-term conservation programme that included re-flooring the interior of the church, we were tasked with carrying out an archaeological investigation of the remains. Monitored by Cadw and commissioned by Menter Môn, this initiative saw two trenches opened within the structure’s footprint, as well as a building survey, centred on the standing ruins of the nave and chancel. We carried out an earthworks survey, too, exploring the land immediately around the church and on the site of the former Benedictine monastery, as well as geophysical surveys of the surrounding landscape to the north and south of the church. So, what did we learn about the island’s ecclesiastical past?

The remains of the nave and chancel of St Dwynwen’s Church, looking south-west. Unusually, this building is oriented north-east to south-west.

A church in context

To set the scene: St Dwynwen’s Church – which, unusually, is oriented north-east to south-west – lies within a slightly undulating landscape that is flanked on its eastern and western sides by exposed rock outcropping that protects the site from prevailing winds. To the west, there is also an ancient dune system while, to the east, the rocky outcrops dip dramatically to form a section of cliffs stretching to small shingle beaches and the sea beyond. The surviving masonry stands within the remains of a semi-circular churchyard that survives as a shallow earthwork and is delineated by a turf-stone wall. Based on a late 18th-century engraving made by Nathaniel and Samuel Buck (Yorkshire-born topographers and engravers, who prolifically produced prints of historical sites across England and Wales), the churchyard housed burials, though no markers can be seen today.

After St Dwynwen’s Church was abandoned in the 18th century, the island was settled by lighthouse keepers and their families, who established two lighthouses overlooking the southern section of the Menai Strait. This one was built in the 19th century, several hundred metres west of its predecessor.

A nearby sub-rectangular earthwork is believed to be either a priest’s house or part of the remains of the medieval Benedictine abbey, and to the north is a series of sub-rectilinear earthworks that extend for some 350m and pick out the outline of nine elongated fields delineated by low turf/soil banks. These have been recognised from LiDAR imagery and are thought to be associated with another small community, albeit one with a rather more secular purpose: working two lighthouses at the extreme south of the island in the late 18th and 19th centuries. The lighthouse keepers and their families also established two boat sheds, a breakwater, a jetty, and a terrace of four pilot cottages that can still be seen today.

The Buck Brothers’ engraving of the church, dating to 1742, was a vital documentary source for the present project team in guiding their investigations.

Frozen in time

Helpfully, historical maps suggest that little has changed concerning development within the central section of the island, where the church remains stand. Maps of 1889 and 1922 clearly show the cruciform shape of St Dwynwen’s, along with its churchyard; in both cases the church is shown as ruinous, labelled as ‘remains of’ (as is the abbey). The D-shaped churchyard was probably originally circular in plan, and was subsequently truncated by the later sub-rectangular field system that is shown cutting across its northern section.

Further clues can be gleaned from the surviving fabric of the church itself. St Dwynwen’s appears to be constructed of at least three phases. The northern portion (representing the nave and chancel), with its low-angled pitched roof, probably dates from the 16th century and appears to have originally stood as a separate unit. This is partly evidenced by the presence of long and short quoins that run up the south-eastern returns – however, within its walls we find features that clearly suggest an earlier incarnation. The presence of three Early English Decorative style windows and their associated moulded stone casements seemingly suggests a medieval date. By contrast, though, the eastern transept has a steeper pitched roof and contains two window openings of the Perpendicular style (with associated tracery), which probably date to the 16th century too.

LiDAR imagery showing the central section of the island: (1) St Dwynwen’s Church; (2) the earthwork remains of a monastic building; and (3) the 19th-century extensive field system.
Historical mapping and documents also helped to guide the recent research. Here we see architect Clough Williams-Ellis’ proposed 1906 restoration plan for St Dwynwen’s Church.

Returning to the Buck Brothers’ engraving, close inspection reveals several features and structures that survive within the archaeological record, including a boundary wall delineating the churchyard curtilage. According to the engraving, this boundary was constructed of a drystone wall; today it is preserved only as a low turfed bank, and it is likely that the upper stone coursing has been robbed (probably at the same time as the masonry from the church) and reused in other buildings on the island that are associated with the later lighthouse community.

Based on the same engraving, there were several structures, probably associated with the church (or the ecclesiastical landscape), that once stood outside the precinct wall of the churchyard but have vanished from view. These include a small, rectangular stone building with window openings; the date and precise whereabouts of this structure are unknown today.

Echoes of the later lighthouse communities: a boat shed (above) and a terrace of cottages (below).

Evaluating disrepair, decay, and destruction

Each element of our fieldwork – evaluation, earthworks survey, and standing building recording – formed an essential archive, and every facet was guided by a desk-based assessment of historical maps and documents. In particular, the Buck engraving of the church, as well as historical mapping, were invaluable to helping us locate our trenches and identify any medieval anomalies. We opened two trenches in total – the largest (Trench 1, measuring 7m by 2m) was dug within the central section of the nave, extending into the chancel area, where we expected to find most of the material from the collapsed roof. In fact, the spread of rubble appeared to represent a partition wall between the nave and chancel, possibly the subsurface foundations of a rood screen.

Above this structure and extending across much of the trench (and the interior of the church) were a series of wind-blown deposits testifying to the building’s roofless afterlife once it had fallen into ruin. There were other clues to its religious use, however: in one corner of the trench, we found the partial remains of what has been interpreted as a probable grave, and as excavation revealed no clear cut for a coffin burial, we suggest that this inhumation was probably a medieval shroud burial. Further human remains were recovered from the base of the trench, suggesting that this space had been used for multiple burials. Above the layer containing these burial remains, and extending across much of the trench, we also found evidence of stone robbing. Based on the condition of the church in the late 18th century and in historical imagery, the stone had probably been reused in the construction of the earliest lighthouse, boat shed, and pilot houses.

Trench 1, cutting into the central part of the nave and chancel areas.

Close by, Trench 2 was opened over a low bank that hinted at the presence of a short section of walling. Sure enough, excavation exposed a continuous stretch of a wall measuring 2.5m by 2m, which connected with a circular tower and the nave to the north. These remains will help us to understand how the church was constructed and, pertinent to this project, record the rate of wind-blown deposition since it was abandoned.

Some of the key features of Trench 1: (above) Thomas Wellicome excavates a partition wall that may have once supported a rood screen, and (below) a deposit of slate tile from the collapsed roof of the church.

While the excavation was ongoing, building surveyors were documenting upstanding sections of the church digitally, work that was complemented by a detailed photographic record of the window and door openings that survive, especially around the eastern section of the church building. Unfortunately, these surveys proved inconclusive, as observations show that most of the elevations have, at one point in time, been repointed (and consolidated), and old masonry has been re-laid, thus complicating the historic sequencing.

As for the wider landscape, in 2020 we applied to Cadw to undertake magnetometer and resistivity surveys in fields and open ground to the north and south of the church. This was granted, and fieldwork was due to commence in the summer of that year; however, due to the COVID-19 outbreak, the project was put on hold until late 2021. When work was able to resume, the geophysical survey set out to investigate potential below-ground anomalies, but – apart from the clear rectangular earthwork that lies south-west of St Dwynwen’s churchyard – no further significant features were located. LiDAR imagery, however, reveals the faint lines of a second rectangular building or annex that lies immediately south of the visible earthwork.

Above & below: Over in Trench 2, the team uncovered the lower coursing of a western wall section

Death, burial, and loss

This decade-long project has uncovered much about the two communities that inhabited the island: the first a medieval monastic settlement that included the construction of the Benedictine complex and St Dwynwen’s Church, and the second involving lighthouse men and their families. Both were probably self-sufficient and had little contact with the outside world.

As for what can be said about the church itself, although the drawn and photographic survey described above proved inconclusive, we were able to establish that St Dwynwen’s is a multi-phased building that dates to the medieval period, probably to the late 12th or 13th centuries – and its dedication suggests that an even earlier ecclesiastical building may have existed on the site. Its churchyard, which may have once had a circular outline, offers further evidence of this; a circular churchyard is sometimes indicative of earlier (Celtic) ritualised activity and reflects earlier ecclesiastical activity. While much of the standing masonry within the northern part of the remains is believed to date to the late medieval or early post-medieval periods, we believe that this building section could be much earlier. Based on the Buck Brothers’ engraving, plus our field notes, the window incorporated into the south-eastern elevation is similar in architectural style, with its tracery remains dating to the Early English Decorative movement of the 13th century.

An SLR surveyor undertaking a standing building survey of the church’s eastern elevation.

Rather more clear during our evaluation was the destructive nature of stone robbing and the collapsed roof. Evidence for stone robbing was also witnessed in the removal of stone from the various elevations around the church – in particular, the southern section of the building. Following the probable systematic destruction and removal of the church fabric, the building appears to have fallen into decay sometime before the publication of the 1742 engraving. It seems, from this point in time, windblown deposits begin to accumulate within the internal area of the church. It is possible that Christianity was waning locally at the time, and the decline in parishioner numbers resulted in the eventual abandonment and disrepair of churches in outposts like Llanddwyn Island and throughout England and Wales. In the same period, though, parishioner numbers in a new form of Christian worship – Methodism – began to ‘congregate’.

The earlier of the island’s two lighthouses – was it built using stone recycled from the ruined church?