15. Citigroup Center
Back in 1970, the architect was going to build a huge skyscraper over St. Peter’s Lutheran Church which was in that spot. So the 915-foot tower ended up being built on silts! Although the design is flawed, construction carried on. Officials said that in 16 years, it will topple over, so the Citigroup Center’s engineering was fixed after a massive project was carried out in secret.