Any city’s history of development is filled with interesting near misses. Here are eight ambitious projects that each could have reshaped a U.S. city, but were instead left on the drawing board.

1. GRAND CENTRAL TOWER // NEW YORK CITY

The biggest train station in the world (by number of platforms), Grand Central Terminal was almost capped by what would been the world’s tallest building. In 1902, William J. Wilgus, chief engineer of New York Central Railroad, envisioned the station with a skyscraper on top. Its hotels and apartments would generate revenue to pay off the final $114 million price tag of the project. (That’s $2.7 billion in 21st-century dollars.) One of the architecture firms to compete for the project designed a 60-story building, which would have been the world’s tallest at the time. But the plan selected by the railroad company, a combination of two other firms’ ideas, scrapped the tower and “only” went 45 feet beneath the surface to displace 3.2 million cubic yards of earth to create the world-famous transportation hub.

2. THE CROSSROADS OF AMERICA PLAN // INDIANAPOLIS

“Want a Preview of Indianapolis of 1978?” blared the headline of a September, 1953 edition of the Indianapolis Star. It said nothing about urban decay, disco or the drama surrounding former (and future) Pacers player Billy Knight. Instead, the story broke news of the city’s planned reorganization, one of several mid-century urban restructurings commissioned to ease the influx of automobiles into downtowns. Indianapolis’ Crossroads of America plan, which the Metropolitan Planning Department finalized in 1958, would have broken the city into four quadrants, one for entertainment, one for business and hotels, one a finance sector, and the last for medical services. Each would have a gigantic parking garage and a subway stop to connect them to downtown. Most impressively, the plan called for helicopter ferry service leaving every 15 minutes from Union Street to the cultural district of Broad Ripple. Some of its more eccentric aspects were a fashion district with open-air runways and a Victorian village meant to replicate the city’s past. As decades passed, the city failed to get started on the plan.

3. POINT PARK CIVIC CENTER // PITTSBURGH

Decades of industry turned the patch of land at which Pittsburgh’s three rivers meet into a mass of docks and railyards, and, in the 1940s, the city looked to redevelop that area. The most insane proposal the city received was from Frank Lloyd Wright. The famed architect’s Point Park Civic Center called for a massive circular structure containing a sports arena, an opera house, movie theaters, and a planetarium. It also would have an aquarium with huge spherical tanks. Two cable-stayed suspension bridges held up by a colossal tower would have connected the center to other areas of the city across the rivers. Although Wright submitted a few scaled-back, more affordable versions to Pittsburgh, the city decided on a more conventional park for that space.

4. THE ILLINOIS // CHICAGO

The Point Park Civic Center was, surprisingly, not Frank Lloyd Wright’s most bonkers unrealized project. That distinction goes to the skyscraper proposal he presented to Chicago’s business elite in 1956. It would have been one mile high, 548 stories, and called The Illinois. The structure was designed to house 100,000 people (about 2.7 percent of Chicago’s population in 1950), and the plans called for atomic-powered elevators that could reach the top at freeway speeds. It would have been the largest building in the world (and still the tallest). Skyscrapers half its size wouldn’t be realized until decades later. The closest The Illinois came to realization was an eight-foot model included in a Museum of Modern Art retrospective on Wright.

5. EXPANDED BART PLAN // SAN FRANCISCO BAY AREA

In 1951, California lawmakers launched a study of the transportation needs of the growing San Francisco Bay Area. The result was BART, the Bay Area Rapid Transit set of rail lines. The original 1956 plan, dredged up by cartographer Jake Coolidge for his master’s thesis at San José State University in 2011, was much vaster than the four-tentacle system that was implemented. It would have touched nine counties (meaning day trips from the city to wine country), and the interlocking of various lines would have allowed for much quicker travel across distances. As the local news startup SFBay.ca pointed out, “George Lucas could take the M train from Lucas Valley station, transfer to the P at 4th and King, and arrive at Facebook in Menlo Park in plenty of time for an early lunch.”

6. THE HELIOCOIDAL SKYSCRAPER // NEW YORK CITY

ManfrediNicoletti and Sergio Musmeci // University of Naples

It’d take an eye-popping building to stand out in Downtown Manhattan, even if it was a skyscraper. The Helicoidal Skyscraper [PDF] would have. Conceived by architect Manfredi Nicoletti and engineer Sergio Musmeci in the late ’60s, the tower would have spiraled up 1854 feet, resembling a big, grey DNA helix shooting up from the tip of Manhattan. Inspired by stay-bridge technology and the muscles of mammals, the design called for three inter-connected hollow cylinders at the core of the building, which would have helped it stay steady against winds and other natural elements. The building never moved past the design phase.

7. THE CAUSEWAY // SANTA MONICA TO MALIBU

Image via the City of Santa Monica, via The Malibu Times

Can you imagine driving from Santa Monica to Malibu in half an hour? John Drescher could. In the 1960s, the millionaire developer/engineer proposed an offshore causeway across Santa Monica Bay, built on artificial islands. The roadway would have bypassed Los Angeles’s famously congested traffic, and the 30,000-foot-long chain of man-made isles could have housed 29,000 people. City planners in Santa Monica were into the idea and paid for a feasibility study. Shoreline residents, led by Gunsmoke star James Arness, were adamantly against it, fearing the destruction of the bay’s natural habitat, and California Governor Pat Brown vetoed the causeway.

8. THE LEANING TOWER OF PIZZA // ANN ARBOR

It’s not the most ambitious item on this list, but if it had been built, everyone who passes through Ann Arbor would take a selfie in front of it. In 1987, Tom Monaghan, founder and then owner of Domino’s Pizza, contracted an architectural firm to build a tilted, 30-floor office building on its corporate campus a few miles outside the Michigan city. Its name? The Leaning Tower of Pizza, of course. Monaghan, a fan of Frank Lloyd Wright, hoped to model it after his Golden Beacon, another of his unrealized plans for a Chicago tower. The project never came to fruition but a 50-foot model of its stands outside Ann Arbor.