Nothing signifies strength, defiance, and ownership more than a wall. Since antiquity, humans have been building walls to enclose, defend or protect something from someone else - whether that be the elements or other peoples.
The earliest discovered evidence of walls come from the temple of Gobekli Tepe (Pot-Belied Mountain) in Urfa, Turkey that dates to around 9,500 BC. Since then city walls have since become a common feature of many a permanent settlement, fortification or city with some examples surviving to the modern day.
Since ancient times, our understanding of wall construction has lead to some of the most incredible feats of engineering known to man. From the Great Wall of China to the Berlin Wall, the following 15 cover some of the greatest wall constructs of all time.
This list is in no particular order and is far from exhaustive.
1. Caesar's Double Walls at the Siege of Alesia Were a Masterpiece of Military Engineering
In 52 BC, Julius Caesar and his legions had managed to trap his Gaulic rival Vercingetorix (and a sizeable Gaul army) inside the walled hill fort of Alesia (Alise-Sainte-Reine today). Wanting to finish his rival once and for all, Caesar immediately set about laying siege to the town in order to force its 80,000 garrison and civilians to surrender.
In order to prevent reinforcements and supplies reaching Alesia, Caesar ordered the construction of a 16 km long wooden and earthwork circumvallation (military investment) to completely enclose the settlement. This enormous wall had 24 redoubts (towers) and was complimented by a series of trenches and stakes.
During the construction, the Romans received word that an enormous Gaulic relief force was being assembled to break the siege. Incredibly Caesar rejected any notion of lifting the siege and built a second, longer wall around the, now inner wall.
This second wall stretched 20.71 km and was built to the same specifications as the inner wall. Both of these walls would withstand a series of spirited Gaulic assaults but ultimately Roman valor would force Vercingetorix and his Gaulic allies to surrender - thus ending the Gallic Wars.
Today, little remains of the actual wall beyond evidence of the earthworks and historical records of the time.
2. The Berlin Wall Was Built to Keep The East Germans In
When the Berlin Wall was built in 1961, its construction would physically divide the East and West of the city for the next 28 years. It would become a symbol of the Cold War and heavily influenced German culture for many years to come.
Unlike many other walls on our list, The Berlin wall wasn't built to defend against attackers. Rather it was raised to keep the local population from fleeing the horrors of the Soviet-led Communist regime of East Germany to the West.
Just before its construction, most of the border with West Germany had become fortified by 1952 and so any 'refugees' only had one route left open to them - through Berlin. Many of the East German refugees were young, trained professionals and by the early 1960's East Germany was rapidly losing its labor force and talent - the government decided to take action.
And so, on the night of the 31st August 1961 trucks, soldiers and an army of workers tore up streets, dug holes, installed concrete poles and barbed wire and cut telephone wires between East and West Berlin.
This wire fence was later replaced with the iconic sturdier concrete block and barbed wire construction that was torn down on November9th, 1989.
3. The Mighty Walls of Constantinople Defended Christendom For Many Centuries
The ancient defensive stone walls of Constantinople (currently Istanbul, Turkey) have surrounded and defended the city for over 1500 years. They were originally built when the city was founded as the new capital for the Roman Empire by Emperor Constantine the Great in 330AD.
The walls would undergo a series of modifications and additions throughout their long history. Its famed double lined Theodosian Walls would be the last great fortification system in antiquity and were one of the most elaborate and complex of all time.
When the fortifications were fully manned, the city was more or less, impregnable to besieging medieval armies. Constantinople's walls would protect the city, The Byzantine Empire and Christendom at large, from marauding armies for centuries.
They would only fail with the advent of gunpowder and massed adoption of siege cannons. The cities walls were finally breached in 1453 when Ottoman forces attacked with overwhelming numbers after bombarding the walls and a six-week siege.
4. The "European Wall of China": The Walls of Ston
The Walls of Ston, in Croatia, are some of the longest of any fortress in the world. Construction began in around 1358 and once completed they would stretch for more than 7 kilometers.
Since the 14th Century, these impressive stone walls have protected the city of Ston, Dalmatia for over 650 years. The Walls of Ston are known colloquially as the "European Wall of China".
Ston was once a major port for the Republic of Ragusa (Dubrovnik) and large segments of it still stand today. Throughout the era of the Republic, the walls were primarily tasked with protected the precious salt pans that contributed to Dubrovnik's wealth, which are still being worked today.
5. The Diyarbakir Walls Are Second Only to The Great Wall of China
Built under the reign of Roman Emperor Constantius the II in the 3-4th Century AD, the Diyarbakir Fortress is located in Sur, Turkey. The material for the walls came from an older roman city of Amida and they are the widest and longest defensive walls in the world after the Great Wall of China.
The walls are made from a variety of stone, black basalt and adobe and have been renovated and repaired throughout history. The towers of the walls were mainly built by the Romans and later reconstructed by the Ottomans when they took over the city in the 15th and 16th centuries.
Today, the walls are mainly complete and ring the city over a 5 km circumference, stand at 10 meters tall and are up to 5 meters thick in places.
The conflict between Turkish and Kurdish forces, since 2015, has resulted in some damage to the fortress and surrounding monuments.
6. Hadrian's Wall Once Marked the Limit of the Civilised World
Built to keep tribes of 'The North' out of the Roman Province of Britannia, Hadrian's wall's construction began in 122 AD. The entire fortification ran from the banks of the River Tyne on the North Sea to the Solway Firth on the Irish Sea.
Contrary to popular belief, the wall lies entirely within England and has never former an Anglo-Scottish Border.
When it was completed, it became the northernmost limit of the Roman Empire and marked a near impenetrable barrier to Ancient Briton tribes to the north.
The wall runs for a total of 73 miles (117.5 km) with mile-castles, turrets and Roman forts built at regular intervals along its length. Although much of the walls material has been 'robbed out' since its abandonment, a significant portion of it is still standing today.
It is one of Britains major tourist attractions and one of its most important cultural icons. It as designated a UNESCO World Heritage Site in 1987.
7. The Aurelian Walls Were Built to Defend Rome From Invaders
The Aurelian Walls, built between 271 and 275 AD, of Rome, superseded the older original 4th Century BCServian Wall. These impressive defensive structures were built to enclose all seven hills of Rome, Campus Martius and parts of the Tiber and the Trastevere district.
Emperor Aurelian made the decision to build his new fortifications as a reaction to barbarian invasions of Northern Italy in 270 AD. Large portions of the city had outgrown their existing Servian walls and were largely undefended.
The entire set of fortifications ran for about 19 km and enclosed an area of 13.7 km2. The walls were primarily made of concrete and were later brick-faced. When they were originally built, the walls were 3.5 meters thick, 8 meters high and had a square tower every 29.6 meters along the wall.
The walls were later doubled in height to 16 meters during the 4th Century AD by Emperor Maxentius. By the 6th Century AD, the walls comprised over 380 towers, over 7000 crenellations, 18 gates, over a hundred latrines and many external windows.
Rome's Aurelian Walls would continue to protect the 'Eternal City' right up to the 19th Century. For this reason, they are remarkably well preserved today with around two-thirds of it intact.
8. The Athenian Long Walls Kept Athens Connected to Its Ports During Sieges
Stretching over roughly 6km each, the Long Walls of Athens protected Athenian's access to their ports of Piraeus and Phalerum during times of siege. They were built over several phases and with the first phase completed in the 5th Century BC in response to Xerxes' invasion of 479 BC.
In 457 BC, a Spartan Army attacked and defeated an Athenian army in an attempt to stop their construction, but to no avail. Construction works of the Phase 1a (their modern denomination) walls were completed soon after which secured access to both ports and enclosed a very large area.
These impressive constructions formed the cornerstone of Athens' defensive strategy and helped them thwart land-only sieges as they would enable the city to maintain access to the sea.
They also effectively rendered Athens and island within the mainland of Greece. During these times it was very difficult to capture walled cities by force and so siege tactics relied on starvation and surrender.
They were not to last, however as the Spartan's had them dismantled in 403BC after their victory during the Peloponnesian War. Persian support later enabled Athens to rebuild them during the Corinthian Wars of 395 to 391 BC.
Records indicate that the walls were still in use by the 1st Century BC. But they were once again dismantled by Roman General Sulla after his victory during the Siege of Athens and Piraeus in 86 BC.
9. The Atlantic Wall Was Built To Keep The Allies Out of Europe
Between 1942 and 1944, Nazi Germany built a network of coastal defenses along much of the coastline of continental Europe. With a planned total length of 2688 km, it formed the backbone of Hitler's so-called 'Fortress Europe' - it would never be fully completed.
This wall was built in response to the perceived need to defend against a future Allied invasion by sea.
The fortifications were built by over a million French workers who were 'drafted' into service. Its construction became a huge piece of Nazi propaganda and its capabilities were highly exaggerated for the media - for obvious reasons.
Although it was called the Atlantic Wall, it was, in fact, a series of enormous coastal gun batteries, mortars, artillery, pillboxes, minefields and other manned static defenses. Although it offered some stiff resistance during the Allied Normandy Invasion, in most places it was quickly stormed and over-run in hours.
Today some parts of it can still be seen, more or less, intact along its entire length from France to the Norwegian Fjords.
10. The Great Wall of China Is Over 2,700 Years Old in Places
One of the Medieval Wonders of the World, the Great Wall of China runs, roughly, East to West across the historical northern border of China. Its construction was originally in response to defend against invasions and raids from Eurasian Steppe hordes.
It officially runs for around 21,196 km or 13,171 miles with the best preserved and maintained section from the Ming Dynasty extending for just over 8,850 km of that total.
Although the Great Wall is 'seen' as one enormous contemporaneous wall it is, in fact, a series of merged walls built over different phases from the 7th Century BC to the 17th Century AD. Although the wall has been rebuilt, maintained and expanded over time most of the existing wall was built during the Ming Dynasty between 1368 and 1644.
What remains of the wall today consists of a series of fortifications made of stone, brick, tamped earth, wood and other building materials. Today, it is estimated, that 33% of the original wall has now disappeared from disrepair to robbing out to demolition works.
Its most visited section, receiving around 70,000 visitors a day, is the Badaling section.
11. The Belfast Peace Lines Are Still In Place
There are few places in the world that have seen the level of sectarian violence similar to that of the streets of Belfast, Northern Ireland. With a heady mix of vendetta's and opposing views on religion and nationalism, 20th Century Belfast bore witness to countless 'troubles'.
In an attempt to keep the peace, British Officials built a series of separation barriers across Northen Ireland to keep Republican/Catholic and Loyalist/Unionist Protestant communities apart. The first of these walls was built in 1969 with as many as 59 being built as of 2017.
Since the Good Friday Agreement of 1998 Peace Lines have increased in height and number, though talks are in place to begin to dismantle and remove them.
These barriers range in length from just a few hundred meters to up to 5 km. Each one is made of iron, brick, and steel and stand at just over 7 meters high with most being situated in Belfast, Derry, Portadown, and Lurgan.
12. The Moscow Kremlin Walls Are Both Beautiful and Deadly
The Moscow Kremlin, simply The Kremlin, is a fortified complex in the heart of the Russian City of Moscow. It is the best known of the Russian Kremlins (Citadels) and includes a series of cathedrals and places behind its iconic walls.
The Moscow Kremlin Wall is the most important part of the Moscow Kremlin Complex that is characterized by its notches and iconic towers. As impressive as the existing masonry walls are the original one was likely built of wood in the 12th Century when Moscow is thought to have been founded.
The original defenses built by Yuri Dolgoruki were destroyed by Mongol-Tartar invaders with the later walls meeting a similar fate in 1365. Stone walls were erected in the 14th Century which was later remodeled during the 15th Century.
Its current highly decorative aesthetics dates from the reign of Czar Alexia Romanov and successive restorations throughout history.
13. The Walls of Troy Are Around 5000 Years Old
Located in Anatolia, Modern Turkey, Troy (Truva or Troya in Turkish) was once a city in late Classical Antiquity. It featured heavily in Homer's classic epic the Iliad and was the setting of the semi-mythical Trojan wars.
Whether the site is the Troy of Homer's epic or not the fortified settlement at Hisarlik in Turkey would have had impressive defenses for the time. Archaeological evidence suggests the first Trojan Walls were erected between 3000 and 2600 BC.
From what has been excavated, it seems the walls surrounded the city and would have been over 5 meters high. The walls were made of limestone and had a series of watchtowers, brick ramparts or elevated mounds that served as protective barriers.
The site shows at least 9 phases of destruction and rebuilding lasting from 3000 BC to between 85 BC and 500 AD.
14. Fort Kumbhalgarh's Walls Are Some The Longest in The World
Fort Kumbhalgarh is an enormous Mewar Fortress situated in the Aravalli Hills n the Rajsamand district of Rajasthan state in western India. It was built during the 15th Century by Rana Kumbha and it was the birthplace of the warrior King of Mewar, Maharana Pratap.
The fortress and its walls are built on top of hill 1,100 meters above sea level. Its frontal walls are as much as 4.5 meters thick with seven fortified gateways. These impressive defenses protected 360 temples that were/are a mixture of Jain and Hindu in origin.
The fortress was in occupation until as late as the 19th Century and is now an open-air museum.
The fortress' wall is over 38 km long making it one of the largest wall complexes in the world, and the second largest fort in Rajasthan after Chittor Fort.
15. The Korean Border DMZ Is a Haven For Wildlife
And last, but by no means least on our list of greatest wall constructions, is a rather topical one. Especially given the latest diplomatic developments in Korea.
The Korean Demilitarized Zone, DMZ, is a border barrier that divides North from South Korea along the 38th Parallel. It was constructed after an agreement between North Korea, China, and the UN in 1953.
The barrier stretches for 250 kilometers and is, on average, 4 km wide along the DMZ. When negotiations are required between the two nations they are conducted in the small Joint Security Area (JSA) near the western end of the DMZ.
Since its construction, there have been some incidents and incursions by both combatants. The period between 1966 and 1969 was particularly tense with skirmishes along the DMZ resulting in the deaths of 43 Americans, 299 South Koreans and 397 North Korean soldiers killed.
Interestingly the DMZ has effectively been untouched by man for over 65 years. It has become, according to the National Geographic Magazine, a haven for wildlife - some of which are endangered.