The area between 48th and 51st Streets, 5th and 6th Avenues, was once a notorious red-light district. Today it’s occupied by New York City’s most famous city within a city, Rockefeller Center. Built by John D. Rockefeller during the height of the Depression, the magnificent art deco complex is comprised of 19 buildings, connected by plazas and underground passageways.

At the heart of the complex is the sunken Lower Plaza, home to an outdoor restaurant in summer, an ice-skating rink in winter, great people-watching year-round, and an ungainly gilded Prometheus. At Christmastime, the famous Rockefeller tree is erected directly behind him.

In Top-of-the-Rock 30 Rockefeller Plaza are the NBC Studios (49th St. between 5th and 6th Aves., 212/664-3700, www.nbcstudiotour.com), where you can peer into the Today show studio window or take a tour. The one-hour tours leave from the New York Experience Store (every 15 minutes 8:30 a.m.–5:30 p.m. Mon.–Sat. and 9:30 a.m.–4:30 p.m. Sun., adults $17.95, children 6–16 and seniors $15.50, children under six not permitted, reservations recommended, www.nbcuniversalstore.com).

Top of the Rock observation deck (212/698-2000, www.topoftherocknyc.com, 8 a.m.–midnight, daily, adults and seniors $18, children 6–12 $13, children under six free) on the 70th floor has the advantage of seeing the Empire State Building.