London Wall was the defensive wall first built by the Romans around Londinium, their strategically important port town on The River Thames in what is now the United Kingdom, and subsequently maintained until the 18th century. It is now the name of a road in the City of London running along part of the course of the old wall between Wormwood Street and the Rotunda junction where St. Martin's Le Grand meets Aldersgate Street. Until the later Middle Ages the wall defined the boundaries of the City of London.
Later Use and Remains:
The wall remained in active use as a fortification for more than 1,000 years afterwards. It was used to defend London against raiding Saxons in 457, and was redeveloped in the medieval period with the addition of crenellations, more gates and further bastions. 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, some of the tallest ruins in the bomb-damaged City were remnants of the Roman wall.
The wall's moat has also left its mark on London; it forms the line of the street of Houndsditch. This was once London's main rubbish disposal site and was notorious for its appalling odour; its name, according to the 16th-century historian John Stow, was derived "from that in old time, when the same lay open, much filth (conveyed forth of the City) especially dead dogges were there laid or cast." The moat was finally covered over and filled in at the end of the 16th century, becoming the present street.