Hadrian’s Wall, also known as the Roman Wall, is the remains of a defensive fortification in the Roman province of Britannia, ran from the banks of the River Tyne near the city of Newcastle and the North Sea to the Solway Firth on the Irish Sea, which was the northern limit of the Roman Empire. The original structure was built by the Roman army on the orders of the Emperor Hadrian, following his visit to Britain in AD 122. For nearly 300 years, the 80 miles long Wall was the north-west frontier of the Roman Empire, which included a number of forts as well as a ditch designed to protect the territory against any possible invasion.

Though the construction of the Hadrian's Wall started in 122 and completed in six years, it was probably planned before Hadrian’s visit to Britain. According to the restored sandstone fragments found in Jarrow, dated from 118 or 119, the wall was constructed, as Hadrian was divinely instructed to keep the empire intact. However, contrary to popular belief, the wall never served as the border between England and Scotland. Scholars believe that the wall may have served as a means of restricting immigration and smuggling into and out of the Roman territory.

Initially, the plan was to build a wall of stone or turf, fronted by a wide and deep ditch. The wall would feature a guarded gate every mile, with two observation towers in between each gate. Finally, 14 forts were added to the wall and between each pair of mile castles lay two towers or turrets, creating a pattern of observation point every third of a mile. The stone wall, with a maximum height of about 15 feet, was around 10 feet wide, which is wide enough for a walkway along the top. However, the width and height of the wall fluctuated according to the construction materials available nearby.

In the east of the River Irthing, the wall was made from squared stone and measured around 10 feet wide and 16 to 20 feet high, while in the west of the river the wall was originally made from turf, measuring 20 feet wide and 11 feet high. Later, it was rebuilt in stone. However, these dimensions do not include the wall's ditches and forts. A large ditch was dug immediately south of the wall, with adjoining parallel mounds, one on either side. Today these mounds are known as the Vallums and their purpose was presumably to protect the rear of the frontier zone.

After the death of Hadrian in 138 AD, the new emperor Antoninus Pius abandoned the Hadrian’s Wall and built the new Antonine Wall.

Gradually, the neglected Hadrian’s Wall fell into ruin and over the centuries became a quarry of stone to be reused in other local buildings. Ultimately, the conservation movement in the 18th and 19th centuries put an end to that, though in the meantime much of the wall had disappeared. It was designated as a UNESCO World Heritage Site in 1987, but remained unguarded, allowing the visitors to climb and stand on the wall, which necessarily threatens the damage of the ancient structure.

On 13 March 2010, the Hadrian Wall was illuminated in a public event, when the entire route of the wall became a romantic dreamland with 500 gleaming beacons. The illumination took place again on 31 August and 2 September 2012, at a digital art installation called ‘Connecting Light’.