The Cincinatti, Ohio Subway. The Queen City's most infamous public works project was the subway system begun in the 1920s in a drained canal bed. Financial problems prevented its completion, but the tunnels still snake between mostly-finished stations under downtown Cincinnati.
Dent School House Tales - In 1942, 5 students vanished; in 1945, 4 students did; in 1952, 3 students did, & in 1955, 7 students did. Supposedly the staff complained about a smell, and "Charlie the Janitor" said it was the old pipes. Rumors spread about Charlie, and the basement was searched. It contained decaying remains of the missing students. Charlie was never found by police, & the school closed shortly after.Now the place is a popular haunted house open during Halloween.
Track 61, the secret train platform beneath the Waldorf-Astoria. The long-abandoned train platform, which allowed VIPs to enter the hotel in a more private manner—most famously it was used by Franklin D. Roosevelt, possibly to hide the fact that he was in a wheelchair suffering from polio. The mysterious track, known as Track 61, still houses the train car and private elevator, which were both large enough for FDR's armor-plated Pierce Arrow car.