From London Cameos, by A.H. Blake:
It is an oft-told tale that the Fire of London started at Pudding Lane and burnt through to Pye Corner, and that, as a contemporary preacher said, it was due to the sin of gluttony. A fat, greedy boy, trying to steal a pie from the King's Baker's oven, is said to have let the fire get at some wood put by to dry, and set the house of light.
There existed here at the corner of Giltspur Street and Cock Lane a tavern called The Fortunes of War, and this figure [of a small fat child] was put up on it to mark the spot where the fire is supposed to have ended …
This small wooden statuette, covered in gold leaf, still stands today. Though Pye Corner seems too coincidental, it in fact derives from Magpie, the name of a pub on the opposite corner from the Fortunes of War.
The Fortunes of War was an ancient public house that was finally demolished in 1910. In the 19th Century it was a favorite stopping place for Resurrection Men, as it was close to the river and the bodysnatchers had a professional interest in drowned corpses. The Humane Society had designated the Fortunes of War as the official place where those drowned in the river were first brought, and the resurrection men had assigned seating, where they waited for custom to come to them.
So famous was the Fortunes of War that Charles Dickens stole it as background for a scene in Tale of Two Cities, where one of his characters, Jerry Cruncher of Tellson's Bank, moonlights as a resurrection man.
When the Fortunes of War was demolished, the Fat Boy was temporarily homeless, until the City and Guilds headquarters was built on the site. He now commands an excellent view of the corner.
So, in one location we have: an ancient site, a monument to the greatest disaster London has ever known, drowned men, bodysnatchers, and the City and Guilds, a charitable institution whose aim is:
For the purposes of all such branches of science and the fine arts and for the advancement, dissemination, propagation, promotion, culture and application of all such branches of science and the fine arts as benefit or are of use to or may benefit or be of use to productive and technical industries especially and to commerce and industry generally or any branch thereof.
In Bookhounds, megapolisimantically speaking this is one of the most powerful locations in London. Not only is it significant in its own right by virtue of being where the Great Fire stopped, it's marked by what amounts to a node of power (the Fat Boy), it still has remnants of necromantic taint (all those drowned souls), and, to cap it all, one of the most significant forces for technical and industrial power in London.
What kind of workings are likely? Causing fires is the obvious one, as is snuffing one out. The Fortunes of War still exists in London's memory, so it ought to be possible to get to the public house, if only for an hour or two. In game terms, the pub was only recently demolished, so it ought to be fresh in London's memory. That might make it a useful hiding place, so long as whoever uses it can stand the horror of drowned men.
For that matter, a working that allowed the user to speak with anyone recently drowned would work here. Or a working that caused a drowning.
Playing on the City and Guilds angle, any working that relied on technology or industry would get a boost if this was used as an anchor. Or, conceivably, any working intended to affect the Royal Family. The Royals traditionally are president of the City & Guilds; currently HRH The Princess Royal is its president. Queen Victoria founded the institution, and her son the Prince of Wales was its first president.
However a location like this is prized. There's likely to be more than one megapolisomancer who wants it for her own. Neophytes should be wary, lest their working be turned against them by someone more powerful, or cunning.