Walls are built for many reasons – mainly to keep people out. The English word 'wall' comes from the Latin, 'vallus' meaning 'a stake' or 'post' and designated the wood-stake and earth palisade which formed the outer edge of a military fortification. Over the centuries many walls have been built across the world. Here are our favourite seven.

The Great Wall, China


The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, built along an east-to-west line across the historical northern borders of China to protect the Chinese states and empires against the raids and invasions of the various nomadic groups of the Eurasian Steppe such as the Mongols and Huns.

Hadrian's Wall, England


Hadrian's Wall, also called the Roman Wall, Picts' Wall, or Vallum Hadriani, was a defensive fortification in the Roman province of Britannia, begun in AD 122 in the reign of the emperor Hadrian. It ran from the banks of the River Tyne near the North Sea to the Solway Firth on the Irish Sea, and was the northern limit of the Roman Empire.

Western Wall, Israel


The Western or Wailing Wall is an ancient limestone wall in the Old City of Jerusalem originally erected as part of the expansion of the Second Jewish Temple begun by Herod the Great. Known to Jews and Christians as the Temple Mount, it was once part of a large rectangular structure topped by a huge flat platform, thus creating more space for the Temple itself and its auxiliary buildings.

Walls of Babylon, Iraq


Babylon, about 85 kilometers south of Baghdad, was one of the great capitals of the ancient world and was associated with King Nebuchadnezzar II, 605-562 BC, who built three walls around Babylon at heights of 14m. The Ishtar Gate in the wall of Nebuchadnezzar II's Babylon was claimed by some to be greater than any of the listed Wonders of the Ancient World.

Sacsayhuaman wall, Peru


Sacsayhuaman is a citadel on the northern outskirts of the city of Cusco, Peru, the historic capital of the Inca Empire. Sections were first built by the Killke culture about AD 1100; they had occupied the area since AD 900. The complex was expanded and added to by the Inca from the 13th century; they built dry stone walls constructed of huge stones. The site is at an altitude of 3,701m.

Walls of Troy, Turkey


Troy was a city in the northwest of the region known in late Classical antiquity as Asia Minor, now known as Anatolia in modern Turkey, just south of the southwest mouth of the Dardanelles strait and was the setting of the Trojan War. The walls of Troy, first erected in the Bronze Age between 3000 and 2600 BC, were its main defense. The walls surround the city, extending for several hundred meters, and at the time they were built they were over 6m tall. They were made of limestone, with watchtowers and brick ramparts, or elevated mounds that served as protective barriers.

Walls of Ston, Croatia


The Walls of Ston are a series of defensive stone walls, originally more than 7 kilometres long, that surrounded and protected the city of Ston, in Dalmatia, part of the Republic of Croatia. Their construction was begun in 1358 and today, it's the second longest preserved fotification system in the world. The Walls of Ston are also known as the "European wall of China".

Words: Wikipedia; Pictures: Getty Images/Huffpost