Grand Central Station, New York.

Grand Central is not only the world's largest (76 acres) and the nation's busiest railway station—nearly 700,000 commuters and subway riders use it daily—but also one of the world's most magnificent, majestic public spaces. The main concourse, 200 feet long, 120 feet wide, and 120 feet is majestic. Overhead, a twinkling fiber-optic map of the constellations covers the egg–blue ceiling. The lower level is a food hall to satisfy the appetite of anyone! A must-see when in New York.