Lincoln Park Zoo

In 1962, workers building a barn at the Lincoln Park Zoo in Chicago dug into the foundation and hit a coffin. The zoo director, Lester Fisher, called the coroner. The coroner told him to call the Department of Health. The Department of Health told him to call the coroner. After enough of that, Fisher gave up, had the grave reburied, and let crews build the barn directly on top of it. Staff in that section of the zoo, the Farm-in-the-Zoo, say the doors have slammed shut on their own ever since.

There was a reason the coffin was there. The land under the zoo was Chicago's original City Cemetery, in use from the 1840s until the city shut it down around 1866 — partly out of fear the graves were leaking into Lake Michigan and the drinking water. In one summer week in 1854, more than 600 cholera victims went into the potter's field. Roughly 4,000 Confederate prisoners who died in a nearby camp were buried here too.

When the city turned the cemetery into a park, it was supposed to move all of them. It didn't. The 1871 fire burned the wooden grave markers and cracked the stone vaults, so most of the remaining graves could no longer be identified. A Northwestern researcher who mapped the old burials estimates more than ten thousand forgotten graves are still down there.

They keep surfacing. In 1998, a dig for a parking garage at the nearby history museum turned up partial remains of 81 people and an iron coffin holding a well-preserved corpse.

One grave was left standing. The Couch Tomb, a 50-ton limestone mausoleum from 1858, was too expensive to move — the only marked grave left from the cemetery, two blank plaques flanking its sealed door. A hotel owner named Ira Couch was said to be inside, with about six others. But the named ones have headstones at another cemetery across town, and Ira Couch appears in no record there.

So nobody knows who's in the one tomb they kept. Everyone else, they buried twice.