Sunday is Groundhog Day, and the nation will watch as Punxsutawney Phil emerges to predict the coming of Spring before diving back underground. New York City’s underground looks a little different from a groundhog’s burrow -- with miles of tunnels and infrastructure that lie deep beneath the city’s surface. On this week's Cityscape, we’re headed underground to explore the New York that exists just beneath our feet, from subway tunnels to buried historical treasures.