This is soo From The Mixed Up Files of Mrs. Basel E. Frankweiler!
New Yorkers, you know how the 6 train ends at Brooklyn Bridge, and they say "Last stop, Brooklyn Bridge/City Hall"? Well that stop is really only Brooklyn Bridge, and is not the original City Hall stop, and the original City Hall stop is actually this beautiful, magical place you see above, by far the most beautiful New York subway station ever made.
But the City Hall station was closed decades ago, for reasons you can read about here, never to be seen by passengers again...
If you stay on the 6 train after they say last stop at Brooklyn Bridge (which you ordinarily would never do, because if for some reason you did want to just head right back up town, you would cross the platform to the uptown side), the 6 has to pass through the City Hall station to turn around and head back uptown! So if you just stay on for a few extra minutes, you can see the lost station!
How cool is that??? I feel like a little kid. I'm dying to do it.