The Great Wall beyond China: ancient defence walls from Beijing to Ulster

Article summary

What this article covers: The Great Wall of China, what it was built for, and how it compares with Rome’s frontier walls in Britain, Ireland’s own boundary earthworks and the cliff fort of Dún Aonghasa.

Who this is for: Travellers and history readers in Ireland, the UK and further afield who want to understand why ancient peoples built frontier walls and which ones they can visit.

Key takeaway: The Great Wall of China, Hadrian’s Wall and Ireland’s Black Pig’s Dyke were all built to mark and control a frontier, and the last two are within easy reach of anyone travelling from Ireland.

Expert insight: “Everyone pictures the Great Wall when they think of an ancient frontier, but Ulster had its own version running through the border counties, and very few visitors have heard of it. Standing on the Black Pig’s Dyke and asking why folklore gave a pig the credit is one of the best introductions to how Irish people explained their own landscape,” Ciaran Connolly, Founder of ConnollyCove

Quick facts:

• China’s first formal survey of the Great Wall, published in 2012, measured the whole network at 21,196 kilometres across 15 provinces.
• Hadrian’s Wall was begun in AD 122, runs 73 miles (117.5 km) across northern England and became a UNESCO World Heritage Site in 1987.
• Dún Aonghasa on Inis Mór is a late Bronze Age hillfort built around 1000 BC and remodelled in the early medieval period.

The Great Wall of China is usually the first structure people picture when they think of an ancient frontier, but it belongs to a much wider tradition of walls, ditches and ramparts built to show where one power ended and another began. Rome built two such walls across northern Britain, Persian kings built one running inland from the Caspian Sea, and in Ireland a long line of earthworks once marked the southern edge of Ulster. If you are planning a trip to China itself, our section-by-section Great Wall of China travel guide covers Badaling, Mutianyu and the wilder stretches in detail.

ConnollyCove, the Ireland-based travel and culture platform founded by Ciaran Connolly, looks at these structures together because the reasons behind them were remarkably similar. This guide starts with what the Great Wall of China was actually for, compares it with Hadrian’s Wall and other frontier works, and then follows the idea home to the Black Pig’s Dyke and the clifftop fort of Dún Aonghasa. The later sections explain which walls you can visit from Ireland, when to go and how each one is being protected.

The Great Wall of China was built to control the northern frontier

The Great Wall of China was built to defend the northern borders of successive Chinese states against nomadic peoples from the steppe, and to control who and what crossed that frontier. It never surrounded China, and it was never a single continuous wall; it is a network of walls, trenches, towers and passes built by different dynasties over roughly two thousand years.

The scale only became clear recently. An archaeological survey run by China’s State Administration of Cultural Heritage and the former State Bureau of Surveying and Mapping from 2007 found Great Wall structures spread across 15 provinces, autonomous regions and municipalities, and it recorded 43,721 heritage sites, including stretches of wall, defence works and passes. Before that figure was released, a preliminary survey had covered only the Ming dynasty walls, which alone extended more than 8,850 kilometres.

The wall separated farmland from the steppe

The question of what the Great Wall separated has a geographical answer. It was designed to protect China’s northern border from raiding peoples living in what is now Mongolia, and although work continued for centuries, most of the surviving structure was rebuilt during the Ming dynasty (1368 to 1644). In practice, the wall ran along the line where settled farming country gave way to grassland, so it divided two ways of life as much as two powers.

Defence was only part of the job. The wall also served as a means of controlling trade and migration, and garrisoned passes allowed officials to inspect goods and travellers moving between China and Central Asia. Caravans following the overland trade routes passed through these gates, which links the wall to the wider story told in our guide to the historic Spice Routes and the ports you can still visit.

The wall is used today as a heritage site and a national symbol

Today the Great Wall is a protected monument, a major visitor attraction and a symbol of Chinese identity. UNESCO added it to the World Heritage List in 1987, and the restored sections north of Beijing receive large numbers of visitors every year. Most of the network, however, survives as ruins in rural areas far from any tourist route.

For visitors based in the capital, a day on the wall usually sits alongside the Forbidden City and the city’s temples and markets, all of which are covered in our list of things to do in Beijing. The restored sections show how the wall looked under the Ming, while the crumbling outer stretches show how much has already been lost.

Construction methods moved from rammed earth to Ming brick

The earliest walls were built from compacted earth, and the brick and stone wall that appears in most photographs is a much later Ming creation. Builders used whatever the local terrain provided, which is why desert sections in the west look very different from the mountain sections near Beijing.

Rammed earth involves compacting soil and clay, often mixed with gravel, straw or lime, inside wooden frames to form solid walls. Some of the oldest surviving sections, in Shandong province, are often dated to around 2,500 years ago, and the technique lasted because it used materials that were available almost everywhere along the frontier. Ming engineers later faced many stretches with fired brick and dressed stone, which is why the sections near Beijing have such sharp, well-defined battlements.

The Great Wall was also a communications system. Beacon towers sent smoke signals by day and fire signals by night, so warnings could be relayed quickly over long distances, while watchtowers sheltered troops and gave them high ground from which to watch the approaches. This network of towers explains much of the wall’s military value, because a small garrison that could call for help quickly was far more useful than a long, empty rampart.

The human cost survives in the legend of Meng Jiangnü

No reliable count exists of how many people died building the Great Wall, but the hardship of forced labour is remembered in one of China’s best-known folk tales. In the legend of Meng Jiangnü, a young woman travels to the frontier to find her husband, who has been conscripted to work on the wall, only to learn that he has died. Her weeping is so intense that a section of the wall collapses and reveals his remains.

The story shows how ordinary people explained a monument built at enormous human cost, and it fits the wider history of conscripted labour described in our introduction to ancient China and its dynasties. Ireland has its own habit of explaining great earthworks through folklore, as the story of the Black Pig’s Dyke shows later in this guide.

Other empires built frontier walls for the same reasons

Rome, Persia and medieval Europe all built frontier walls to mark the edge of their territory, regulate movement and show their power. The Great Wall is by far the longest, but its purposes match those of its Roman and Persian counterparts closely.

Hadrian’s Wall is the comparison most readers in Ireland and Britain know best. It was begun in AD 122 under the Emperor Hadrian and ran from Wallsend on the River Tyne to Bowness-on-Solway, with soldiers garrisoned in large forts, smaller milecastles and turrets, and its gates may have served as customs posts. The wall marked the boundary between Roman Britannia and unconquered Caledonia, and it lies entirely within England, so it has never formed the Anglo-Scottish border. Our full guide to Hadrian’s Wall, its forts and its walking routes covers visiting in detail, and the man behind it is profiled in our article on Emperor Hadrian.

Some historians have even linked the two walls directly. One proposal holds that Hadrian may have been influenced by travellers’ accounts of the Great Wall of China, built some two hundred years earlier, although other scholars have challenged the idea. Whether or not the connection is real, both walls show empires choosing to fix a frontier rather than keep expanding. Wikipedia

Rome also built other frontier lines. The turf-built Antonine Wall of AD 142 in central Scotland briefly replaced Hadrian’s Wall before it was abandoned, and it was declared a World Heritage Site in 2008. On the continent, the Limes Germanicus ran for more than 500 kilometres along Rome’s border with the Germanic peoples, and the wider reach of Roman engineering is explored in our article on the legacy of the Roman Empire. Further east, the Sasanian Persians built the Gorgan Wall in what is now Iran, the Byzantine Anastasian Wall protected the approaches to Constantinople, and the medieval Walls of Ston in Croatia guarded the salt pans of the Republic of Ragusa.

Wall	Built	Scale	Main purpose	Recommendation for travellers from Ireland
Great Wall of China	From the 7th century BC; most surviving sections Ming (1368 to 1644)	21,196 km across all dynasties	Frontier defence, trade control, signalling	Worth a long-haul trip via Beijing
Hadrian’s Wall	From AD 122	73 miles (117.5 km)	Roman frontier and customs control	The easiest ancient frontier to visit from Ireland
Antonine Wall	AD 142	Turf wall across central Scotland	Short-lived Roman frontier	Combine with a trip to Glasgow or Edinburgh
Limes Germanicus	Roman period	More than 500 km	Rome’s German frontier	Best suited to Roman history specialists
Black Pig’s Dyke	Prehistoric	Stretches between the Bundoran area and Newry	Boundary of ancient Ulster	A short drive from Belfast or Dublin
Dún Aonghasa	Around 1000 BC, remodelled around AD 800	Clifftop fort with three stone walls	Defence of a single stronghold	Essential on any trip to the Aran Islands

Ireland built its own boundary earthworks beyond Rome’s reach

Ireland was never part of the Roman Empire, so it has no Roman walls, but it does have long prehistoric earthworks that early antiquarians compared directly with the Great Wall of China. The best known is the Black Pig’s Dyke, a series of banks and ditches across the southern edge of Ulster.

Early accounts described the dyke as a once continuous wall from Bundoran on the Atlantic to Newry at the head of Carlingford Lough, forming the ancient boundary of Ulster. It also goes by names such as the Dane’s Cast, the Black Pig’s Race and the Worm Ditch, and the word dyke covers both the ditch and the earthen rampart built from the excavated soil. The China comparison is not new either: Canon Lett described related earthworks in the Ulster Journal of Archaeology in 1897 under the title “The Great Wall of Ulidia”.

How continuous the dyke really was has long been debated. De Vismes Kane presented his first survey to the Royal Irish Academy in 1909 and published a second, correcting paper in 1917, and travellers today will find separate surviving stretches rather than one unbroken line. Several sections lie in the border counties, which makes the dyke an easy addition to the routes in our Northern Ireland travel guide. Ireland’s ancient defences also went below ground, as our piece on underground cities from Cappadocia to County Down explains.

The black pig legend gives the dyke its folklore

Folklore credits the dyke to a magical black pig rather than to human builders. One recorded version says that when the three sons of Tuireann set out to take revenge on a druid, he escaped by turning himself into a black pig, and the earthworks of northern Ireland were attributed to that pig. A prophecy linked to the story warns that when the black pig reaches Athlone and cannot cross the Shannon, the world will end.

The sons of Tuireann belong to the same mythological cycle as the gods described in our guide to the Tuatha Dé Danann, and the shape-changing pig sits comfortably alongside the beings in our guide to creatures from Celtic mythology. The legend plays the same role as the story of Meng Jiangnü in China, giving a human explanation for a structure whose origins had been forgotten. Irish country people treated other ancient earthworks with similar caution, and the beliefs that protected ringforts and lone hawthorns are covered in our article on Ireland’s fairy trees.

Dún Aonghasa shows how Irish builders defended a clifftop

Dún Aonghasa on Inis Mór, the largest of the Aran Islands, is Ireland’s most dramatic ancient defensive site, and it shows a different approach from the frontier walls above. Instead of guarding a long border, its builders surrounded a single stronghold with massive stone walls and used a sheer sea cliff as the final barrier.

Archaeologists describe it as a late Bronze Age hillfort built around 1000 BC and remodelled in the early medieval period, possibly around AD 800, and it has been a National Monument in state care since the late nineteenth century. The fort has three massive drystone walls, and outside them lies a chevaux-de-frise, a dense band of thousands of jagged upright stones that surrounds the fort from cliff to cliff to slow down attackers. Excavations found evidence of prehistoric metalworking, houses and burials, which links the site to the craft traditions described in our guide to ancient Celtic art forms.

The setting is part of the experience. The Aran Islands are an extension of the Burren limestone country of County Clare, and all three islands are Gaeltacht areas where Irish is the main language, so a visit pairs well with our article on Burren folklore. The myths attached to Ireland’s western headlands, which our guide to the lore of Ireland’s rugged coastline explores, give useful context before you stand at the cliff edge.

Ancient walls from China to Ireland can be visited on very different budgets

Hadrian’s Wall, the Black Pig’s Dyke and Dún Aonghasa can each be visited on a short trip from Ireland, while the Great Wall of China needs a long-haul journey and careful planning. The practical differences between them are large, so it helps to match the wall to the time you have.

When you visit Hadrian’s Wall, the central section offers the most dramatic scenery, and a recognised National Trail, the Hadrian’s Wall Path, follows the wall from Wallsend to the Solway Firth, while a railway runs parallel to it between Newcastle and Carlisle. Travellers starting in Northern Ireland can fly from Belfast to Newcastle, and our Belfast travel guide is a useful starting point for planning the journey in either direction.

You can see Dún Aonghasa for yourself by taking a ferry or a short flight to Inis Mór. The fort is about 1 km from the visitor centre over rising ground; the final section crosses rough natural rock, and there is no fence or barrier at the edge of the 87-metre drop, so sturdy footwear and care in windy weather are essential. The Black Pig’s Dyke is easier still, since several stretches lie within a short drive of Belfast or Dublin, and our Ireland travel guide covers the wider routes through the border counties and the west.

The Great Wall of China needs more preparation. Badaling is the most visited section because it is close to Beijing and easy to reach, while Huanghuacheng offers lakeside views where parts of the wall run down into the water. All of these sites form part of the global heritage network described in our overview of UNESCO World Heritage Sites.

Conservation pressures look similar on every ancient wall

Every wall in this guide faces erosion, visitor pressure and occasional deliberate damage, and the response in each case is a balance between public access and protection. The Great Wall faces this on the largest scale.

The five-year Chinese survey concluded that a large amount of the wall has collapsed and that only the foundations survive in some sections, and the wall has been heavily damaged by human activity, infrastructure development and tourism. News reports in 2023 described construction workers in Shanxi province using an excavator to widen a gap in an earthen section as a shortcut, which led to their arrest and to wider debate about protecting unguarded rural stretches. UNESCO’s World Heritage listing for the Great Wall sets out the criteria under which the whole network is protected.

Hadrian’s Wall has had its own losses. The central section near Housesteads was where the Sycamore Gap tree stood until it was felled in September 2023, and visitors can still walk to the spot where it grew. The lesson for travellers is the same everywhere: stay on marked paths, never climb on unrestored masonry, and ask permission before crossing farmland to reach earthworks such as the Black Pig’s Dyke.

Current conditions and seasonal information follow regular patterns

Spring and autumn are the most comfortable seasons for visiting most of the walls in this guide, while summer brings the largest crowds and winter brings short days and harsher weather. These patterns repeat every year, but opening times, ticket prices and transport timetables change, so check official sources before you travel.

Around Beijing, spring and autumn usually bring mild temperatures and clearer views, summer is hot and busy, and winter is cold but much quieter on the restored sections. For Hadrian’s Wall, late spring and early autumn tend to offer the best balance of weather and visitor numbers, and Northumberland’s weather can change quickly in any month. On the Aran Islands, ferry and flight services depend on sea and wind conditions, so leave some flexibility in your plans and check with the operator on the day. The Black Pig’s Dyke sits mostly on farmland, which makes late spring to early autumn the easiest time to walk the surviving stretches.

Explore more ancient sites and Celtic legends on Connolly Cove

The Great Wall of China, Hadrian’s Wall and the Black Pig’s Dyke tell the same story in three different places: people building a line on the ground to say where their world ended. ConnollyCove produces guides to Irish heritage, Celtic mythology and travel destinations worldwide, and we are always interested in the points where those stories meet. Start with our guide to Hadrian’s Wall for a frontier you can reach in a weekend, or read about the Tuatha Dé Danann to follow the black pig legend back to its mythological roots.

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