We are not talking about the subways, or the basements, or the parking garages, or the money vaults, or the underground shopping arcades or the train stations or the sewer systems or the telephone cables or the rat nests. Nor do we mean the organized crime rings or the drug smugglers or the sex merchants or the undercover agents, or the palm-greasing or the deal-breaking or the star-making or the muckraking, or the illegal immigrants or the sweatshop slaves or the children crammed into tiny homes, or the secret interlocking passageways that run between private people’s hearts. No, we are talking about a real city, a parallel city whose foundations rest on the bottom of New York Harbor. It is a city made up entirely of things that the people in the world above it have forgotten, all that they have decided, deliberately or otherwise, to cast into the ocean.

Now, you probably already have an image in your mind of what this lost city might look like. You probably imagine people riding those giant-front-wheeled bicycles down streets bustling with bustled women, to the tune of ragtime music. Or maybe you envision trumpeting jazz bands, real-live swing dancers, or speakeasies, or white gangsters. Maybe you’re thinking of robber barons wearing monocles while smoking pipes in palatial homes, or scrappy, good-natured newsboys in tweed caps shouting “Extra! Extra!” Or perhaps you’ve even drawn a mental picture, not yet painted-by-numbers, of billowing sailing ships and men in powdered wigs. But the lost city is no warehouse for nostalgia—not a showcase of the versions of the past that exist only in the present, created out of a mix of thin air and our even thinner ability to see the beauty of the current moment. No, the lost city—and there may well be other lost cities, lurking beneath the Seine or the Yangtze or the Crimean or the Nile or the Baltic or the Ganges or the Amazon or the Danube or the Amsterdam canals, but here we are speaking only of New York—contains only things that we have truly abandoned, created exclusively out of what we believe to be lost forever.