The London Wall is a defensive wall that encircled the City of London.
The wall was built between 190 and 225 AD, it continued to be developed by the Romans until at least the end of the 4th century, making it among the last major building projects undertaken by the Romans before Britannia looked to its own defences in AD 410.
Along with Hadrian’s Wall and the road network, the London Wall was one of the largest construction projects carried out in Roman Britain. Once built, the wall was 2 miles long and about 6 m high, encircling the entire Roman city.
Despite Londinium being abandoned and left to ruin by the Romans, the wall remained in active use as a fortification for more than another 1,000 years. It was repaired when Anglo Saxon rule was returned to London by Afred the Great during a period of Viking sieges and raids, where he carried out building projects to rebuild crumbling defences, recut the defensive ditch (Roman fossa that encircled the walls of Londinium) and found the re-settlement of Lundenburg within the walls.
The wall was further modified in the medieval period, with the addition of crenellations, gates and bastion towers. This formed part of a defensive line that incorporated The Tower of London, Baynard’s Castle and Montfichet’s Tower.
It was not until as late as the 18th and 19th centuries that the wall underwent substantial demolition, although even then large portions of it survived by being incorporated into other structures. Amid the devastation of the Blitz in WW2, some of the tallest ruins in the bomb-damaged city centre were actually remnants of the Roman wall.
The ruins are beneath street level, in an underground car park adjacent to the Museum of London on the A1211.