Although there are plenty of monuments (with a small “m”) around London, there is only one Monument (with a large “M”): that to the Great Fire of London.
The Great Fire of London, which raged through 400 acres of the city within the original Roman walls in September 1666, destroyed almost 90% of the city and left most of its residents homeless. The fire burned for up to four days and spread quickly from the bakery in which it started, helped mainly by prevailing winds, an abundance of theoretically banned wooden buildings, which encroached over the roads in their upper stories until they were almost touching one another, and the apparent reluctance of residents to help extinguish the fire. (Many fled from the fire; at first, to other parts of the city, and subsequently in scenes of panic through the city gates.)
The Lord Mayor of the time (Thomas Bloodworth) is also apportioned a large part of the blame, as on arriving on the scene in the middle of the night, he declared “Why did you wake me? A serving lady could piss out that fire”, then returned to bed, refusing to allow buildings to be demolished to form fire breaks.
The Monument was erected during the re-building of the City of London five years later, having been designed by Sir Christopher Wren. It stands on the original site of St. Margaret’s Church in Fish Street and its height, at 62 metres, is the exact distance from the starting point of the fire, in a bakery in Pudding Lane. At the time, it would’ve towered over the surrounding buildings; now, it provides visitors with a viewing platform to the nearby skyscrapers and river Thames at 311 steps above street level. It remains the tallest isolated stone column in the world.