London, England

London is the capital of England and the city where Carlisle Cullen was born. He grew up and spent the first part of his life there, until he was turned into a vampire at the age of 23, when he stumbled across a coven of vampires living in the sewers. It is hinted that his father also lived here.

England at the time was very well known for its witch hunting activities, hence Carlisle having to go into hiding after his transformation. In the same period, however, London had no sewers, which were built only in Victorian times, when the population swelled from a few tens of thousands people to a few millions people - Stephenie Meyer's mention of them must therefore be treated as historical license in writing fiction.

Role in the Twilight series
In the 1600s, Carlisle was hunting vampires, witches and werewolves in the city, after taking over the role from his father. He was far more gifted than his father at finding true monsters, and stumbled across a coven of vampires living in the London sewers. After gathering together an angry mob, he tried to flush out and destroy the coven but was bitten and left writhing in agony as the party pursued the vampire that had attacked him. He managed to crawl into a cellar and hide in a pile of potatoes, where he completed the painful three-day transformation into a vampire. He was so distraught and repulsed by what he had become that he retreated to a cave in the mountains far from humans, where he would be in no danger of hurting anyone, and attempted to starve himself to death. This failed, however, but he was so thirsty that he attacked a herd of passing deer and sated his thirst with their blood. He realized that he could survive by drinking only animal blood, and was able to regain some of his inner peace.

Alistair, a gloomy and misanthropic English vampire who acts as a witness for Renesmee Cullen, but flees, fearing the Volturi's wrath, is also believed to be from London. He is the only friend of Carlisle's from his early life as a vampire, and it is presumed that they met when Carlisle still lived there.