Pennsylvania Station in New York City is one of the busiest stations in the world, with trains belonging to Amtrak, Long Island Railroad, and New Jersey Transit all stopping there.  It was opened in 1910 by the Pennsylvania Railroad, part of a massive project to improve its access to NYC that also included tunnels under the Hudson and East rivers and Sunnyside Yard in Queens.  The fabulous Beaux Arts-style headhouse was demolished in 1963 to make way for the current Madison Square Garden.

The station as it exists today is a multi-level labyrinth of concourses, stairways, access tunnels, and subway lines between the street and the railroad platforms.