"Stepping into the enormous main concourse of this landmarked architectural jewel—with its sweeping granite staircases, hulking columns and 38-meter (125-foot) ceilings painted with night-sky constellations—can be a jaw-dropping experience. What’s even more incredible, though, is the sheer number of people who use it as a commuter hub day in and day out (more than 750,000 train and subway passengers every weekday). Wander around the shops, head down to the basement food court for a bite and to marvel at the crowds hurrying by—and if you get jostled, don't take it personally."