Defensive wall

A defensive wall is a type of fortification built to shield a settlement, like a city or town, from attackers. These structures could be as simple as wooden palisades or earthen mounds, or as complex as full military fortifications featuring curtain walls, towers, bastions, and gates. Used from ancient times into the modern era, they enclosed settlements and are commonly called city or town walls. However, some walls—such as the Great Wall of China, the Walls of Benin, Hadrian's Wall, the Anastasian Wall, and the Atlantic Wall—stretched far beyond a single city to enclose entire regions or mark territorial boundaries. In mountainous areas, defensive walls called letzis were paired with castles to block valleys from attack. Beyond defense, many walls carried symbolic weight, representing the status and independence of the communities they surrounded.

Surviving ancient walls are mostly made of masonry, though brick and timber versions also exist. Builders often incorporated natural features like rivers or coastlines into the wall’s design to improve its effectiveness, depending on the local terrain. Walls could only be crossed through designated city gates and were frequently reinforced with towers. The practice of building such massive walls began in prehistory, was refined during the rise of city-states, and continued energetically into the medieval period and later in parts of Europe. Simpler defensive walls of earth or stone, built around hillforts, ringworks, and early castles, are usually called ramparts or banks.

**History**

**Mesopotamia** Walls have been nearly essential for cities from very early history onward. Uruk in ancient Sumer (Mesopotamia) is one of the oldest known walled cities. Earlier, the proto-city of Jericho in the West Bank had a wall as early as the 8th millennium BC. Europe’s earliest known town wall is at Solnitsata, built in the 6th or 5th millennium BC. The Assyrians used large labor forces to construct new palaces, temples, and defensive walls. Babylon became famous partly due to Nebuchadnezzar’s building program, which expanded its walls and created the Ishtar Gate. The Persians built defensive walls to protect their territories, including the Derbent Wall and the Great Wall of Gorgan, placed on either side of the Caspian Sea to guard against nomadic groups.

**South Asia** Some settlements in the Indus Valley civilization were fortified. By about 3500 BC, hundreds of small farming villages dotted the Indus floodplain, many with fortifications and planned streets. At Kot Diji, stone and mud brick houses were clustered behind massive stone flood dykes and defensive walls, as neighboring communities constantly quarreled over prime farmland. Mundigak (around 2500 BC) in present-day southeast Afghanistan had defensive walls and square bastions made of sun-dried bricks.

**Southeast Asia** The idea of a city fully enclosed by walls was not fully developed in Southeast Asia until Europeans arrived. Burma was an exception, with a longer tradition of fortified walled towns; towns there had city walls by 1566. Rangoon in 1755 had stockades made of teak logs on a ground rampart, fortified with six city gates, each flanked by massive brick towers. Elsewhere in Southeast Asia, city walls spread in the 16th and 17th centuries as cities grew rapidly and needed defense against European naval attacks. Ayutthaya built its walls in 1550, and Banten, Jepara, Tuban, and Surabaya all had theirs by 1600; Makassar had walls by 1634. Gelgel relied on a sea wall as its main defense. Cities without full walls at least had a stockaded citadel—a wooden-walled area housing the royal citadel or aristocratic compounds, as seen in Surakarta and Aceh.

**China** Large rammed earth walls were built in ancient China from the Shang dynasty (around 1600–1050 BC), as seen at the capital of ancient Ao. Stone walls appeared during the Warring States period (481–221 BC), but mass conversion to stone architecture did not begin until the Tang dynasty (618–907 AD). Sections of the Great Wall were built before the Qin dynasty (221–207 BC) and later connected and fortified under the Qin, though its present form is mostly a Ming dynasty (1368–1644 AD) engineering feat. Pingyao’s large walls are one example. The Forbidden City’s walls in Beijing were established in the early 15th century by the Yongle Emperor. According to Tonio Andrade, the immense thickness of Chinese city walls prevented larger cannons from being developed, because even industrial-era artillery struggled to breach them.

**Korea** Eupseongs, or city fortresses, served both military and administrative roles and were built from the time of Silla through the end of the Joseon dynasty. During the Joseon period, eupseongs were modified, renovated, and new ones were constructed. However, in 1910 Japan, as the occupying power of Korea, ordered their demolition, destroying most of them. Studies of the ruins and reconstructions of these ancient city walls are now underway at some sites.

**Europe** In ancient Greece, large stone walls were built in Mycenaean Greece, such as at Mycenae, famous for its huge stone blocks in cyclopean walls. In classical Greece, the city of Athens...