The cover of a 1911 Moses King guidebook predicted New York City's future pretty accurately.

David W. Dunlap has an incredibly fun slideshow on the New York Times site, which recalls urban planning from NYC’s past that was wildly bold and wholly unrealistic. An excerpt:

“Sobersided planners and wide-eyed visionaries thought this astonishing pace of transformation would never abate. A dreamer named W. Parker Chase proposed in 1932 that the 50 million people living in New York City 50 years on would ride vacuum-tube escalators and take air taxis to their 250-story office towers. The Regional Plan Association envisioned a 1,200-foot-long bathhouse complex at Great Kills Park on Staten Island. Robert Moses, who usually had the power to get things done, tried to persuade the United Nations to build a Brasília-like center at Flushing Meadow Park in Queens. (Midtown Manhattan, he warned in 1946, would by then ‘not be a proper, dignified and practical location’ for the United Nations.)

Dr. John A. Harriss, a distinguished expert on traffic control, went as far as to propose damming and draining the East River, before replacing it with a five-mile-long network of vehicular and train tunnels topped by boulevards and promenades. Pure folly? Not to the advocates of Westway, a highway that would have tunneled through landfill in the Hudson River until the plan was scuttled in 1985.”