As Mexico City archaeologists sort through the surreal array of Aztec sacrificial skulls recently uncovered while excavating their city's subway system, it's worth remembering that parts of the London Underground were also tunneled, blasted, picked, and drilled through a labyrinth of plague pits and cemeteries.


In her excellent and morbidly fascinating book Necropolis: London and Its Dead, author Catharine Arnold describes in detail the subterranean presence of corpses found throughout the British capital. To no small extent, she makes clear, dead bodies were basically buried everywhere, to the point that, as Arnold pithily states, "London is one giant grave."


Here are just a few of my favorite examples, all of them taken from Arnold's book, of how London is saturated from below with corpses, and I'd encourage anyone interested in this sort of thing simply to buy a copy of Necropolis.

Finally, at the end of this post, we'll get back to how all these bodies affected the construction of the Tube—London's subway—which is why this post was started in the first place.


London Hospital students play football on hospital grounds; photo courtesy Getty Images

Hollow Ground

The London Hospital maintained its own on-site burial ground for six years, from 1849 to 1854. However, Arnold explains, "burials continued until about 1860, with porters acting as gravediggers." Somewhat astonishingly, we learn that housing projects for the medical staff were then built over these old graveyards—and the coffins were not very far below the surface.


As Arnold describes, this made for some rather unsafe ground conditions:

The remaining part of the burial ground became a garden for nurses and medical students, complete with tennis court, "where they are in the habit of capering about in their short times off-duty, and where it sometimes happens that the grass gives way beneath them—an ordinary occurrence when the subsoil is inhabited by coffins!"


In other words, these tennis-playing nurses "capering about" on their grass tennis courts would occasionally and literally fall through the surface of the earth only to find themselves standing in the rotting coffins hidden under the soil, an infernal honeycomb of badly tended graves like something out of Dante.

This image—of women frolicking in their 19th-century sports gear suddenly falling into coffins—is absolutely astonishing and surely belongs in a movie coming soon to a cinema near you.


Ooh, That Smell

Far more horrifically, some local churches got in on the financial action of corpse disposal by accepting dead bodies—along with the high fees associated with their interment—only to do nothing at all with the corpses but toss them down into the cellar.


One church was so bad, Arnold writes, that its parishioners would often pass out from the horrible smell of rotting and partially liquified bodies wafting up from below.


Photo courtesy Fox Photos/Getty Images

A particularly nightmarish location described by Arnold is Enon Chapel, a Baptist church founded "as a speculative venture." That is, the minister—a Mr. W. Howse—was in it purely for the money.


Arnold's own description of what happened next says it best:

Worship there was a dangerous business; for members of the congregation frequently passed out—yet, because nobody guessed at the minister's appalling secret, it never occurred to them that the cause of their sickness lay beneath a flimsy layer of floorboards, in the vault of the chapel. In warm, damp weather, local residents were assaulted by a peculiarly disgusting smell. Occasionally, when a fire was lit in a nearby building, an intolerable stench arose, which did not originate from the drains. Vast numbers of rats infested the houses; and meat exposed to the atmosphere turned putrid after an hour or two.


The parishioners could even taste it, apparently: an acrid, oily slick on their tongues, resulting from the humid corpse-fog that filled the church, a kind of artificial weather system created by the dissolving bodies of the dead jumbled up beneath the floorboards.

Mind-bogglingly, when all of this was finally discovered, how many corpses do you think London city authorities found down there? Several dozen? A few hundred, perhaps?


They found twelve thousand corpses. 12,000 corpses all turning into jello and contaminating the local water supply.

The Unforgettable Fire

Yet those churchgoers were lucky to escape with their own lives. At times, Arnold writes, London's urban burial grounds simply exploded, their cheap coffins dangerously over-pressurized from within with corpse gas.


Image courtesy Getty Images

The resulting subterranean infernos, for the most part limited to the crypts and basements of churches, were physically repellent and not at all easy to extinguish. "In the 1800s," Arnold writes, "fires beneath St. Clement Dane's and [architect Christopher] Wren's Church of St. James's in Jermyn Street destroyed many bodies and burned for days."


To help prevent these corpulent bombs from bursting, sextons of the churches were required to "tap" the coffins now and again; this tapping would jostle the bodies within and thus "facilitate the escape of gases which would otherwise detonate from their confinement."

A Pyramid to Rival Giza

We've looked at the design and construction of vertical cemeteries before here on Gizmodo, but necropolitan entrepreneurs in London were looking into this nearly 200 years ago. Why bury, in other words, when you can build?


Specifically, Arnold explains, an architecturally inclined businessman named Thomas Willson once "proposed a huge pyramid for Primrose Hill. At an estimated cost of £2,500, this massive mausoleum, higher than St. Paul's, would contain five million Londoners."


Intended to invoke solemnity and inspire awe, Willson's colossal geometric structure was to be funded through subscription and run by a corporation called the Pyramid General Cemetery Company. As Arnold describes it:

Constructed from brick, with granite facing, the plans comprised a chapel, office, quarters for the Keeper, Clerk, Sexton and Superintendent, four entrances and a central ventilation shaft. A series of sloping paths would allow bodies to be moved. Each catacomb took up to twenty-four coffins and could be sealed up after all interments had been completed. Resembling a beehive, it would be a thing of awe and wonder to all who saw it.


The pyramid was never constructed, of course, but perhaps in our own era of London megaprojects, some brick and granite Giza might yet emerge on the marshy edges of town to support and protect the dead of southeast England.

Drill, Baby, Drill

All of which finally brings us to the real reason I started writing this post, which was to tell the story of how these corpses—the city absolutely littered with burial grounds and plague pits—came to influence the construction of London's Underground train system. It's a brief anecdote, but it's both ghoulish and interesting.


Photo courtesy Fox Photos/Getty Images

As Arnold points out, there is an otherwise inexplicable shift in direction in the Piccadilly line passing east out of South Kensington. "In fact," she writes, "the tunnel curves between Knightsbridge and South Kensington stations because it was impossible to drill through the mass of skeletal remains buried in Hyde Park."


Put another way, the ground was so solidly packed with the interlocked skeletons of 17th-century victims of the Great Plague that the Tube's 19th-century excavation teams couldn't even hack their way through them all. The Tube thus deviates SW-by-NE to avoid this huge congested knot of skulls, ribs, legs, and arms tangled in the soil—an artificial geology made of people, caught in the throat of greater London.


Image courtesy Hulton Archive/Getty Images

Thus, like the example of the Aztec skulls unearthed by subway crews in Mexico City, London's Tube also sits atop, cuts around, and tunnels through a citywide charnel ground of corpses, its very routes and station locations haunted by this earlier presence in the ground below.


For many more gruesome and interesting stories of London's dead, check out a copy of Necropolis.

Lead image courtesy Getty Images/Oli Scarff