I love hidden gems. Better yet, long-forgotten (until now) gems lying deep beneath the surface of one of my favorite cities, NYC. Huffington Post recently posted photos of an abandoned City Hall station from 1904. The station closed in 1945 due to an unsafe gap at the platform, but it is still beautifully preserved. Take the 6 train to the end of the line and get off at the Brooklyn Bridge stop. As it loops back uptown, you can find this station. Apparently there is a trick to check out the station... check out the article here.
photos courtesy of Huffington Post.