The Magician’s Nephew is a children’s novel by C. S. Lewis published in 1955. It is a prequel to the more famous ‘the Lion, the Witch and the Wardrobe’; it explains some of the events, including how the lamp-post and the White Witch ended up in Narnia.
In the story, two children, Digory and Polly, meet while playing in the adjacent gardens of a row of terraced houses. The houses are connected through the attics, allowing the children to travel along the row of houses and accidentally end up in a magician's secret room. Through various events they end up in another world called Charn, where they meet Jadis, who will later become the White Witch. While trying to escape they bring Jadis back into London, which she immediately tries to conquer.
After styling herself Empress, someone mockingly refers to her as the ‘Hempress of Colney ‘Atch’. (Colney Hatch being the name of a small historical district which is now part of Barnet).
“As if it were the most ordinary thing in the world, she stretched up her arm and wrenched off one of the cross-bars of the map-post. She tossed her new weapon up into the air, caught it again, brandished it, and urged the horse forward.”
They manage to remove her from London but accidentally end up in Narnia instead; the piece of the lamp-post later acts a seed from which the lamp-post featuring in ‘the Lion, the Witch and the Wardrobe’ grows.
###########################################################################################
While the precise location of these events within Colney Hatch is not stated, the prevalence of terraced houses and old-fashioned lamp-posts on this street suggest it could be... right here.
This cache is part of my ‘Fictional London’ series, check this list to see them all (more to come).