Grand Central secrets

The Grand Central Terminal Main Concourse, was bustling with Christmas crowds, as I took this picture. Little did I suspect at the time, that GCT once, in 1957, housed an actual American Redstone missile. Or, that a "secret" sub-basement containing the AC/DC converters, known as M42, lies under the Terminal. The exact location of M42 remains a closely guarded secret and cannot be found on maps.