One of New York's best-kept secrets is the abandoned City Hall subway station, a beautiful relic of the system's earliest days. Board a downtown 6 train and—with a hint of rebellion—stay on the train after the “last stop” call. Move to the right side of the car. When the train begins to move, it turns around through the empty station—a marvel of architecture and old New York.

The Staten Island Ferry is a New York City icon in all its orange glory. The crossing passes Ellis Island, the Statue of Liberty, busy shipping lanes, and ever-changing harbor traffic, with Manhattan, Brooklyn, and New Jersey all visible along the way. The ride is complimentary (and priceless); the experience is different each time, because of the weather and boat traffic.

Many visitors are surprised to learn that the Statue of Liberty's internal structure was designed by Gustave Eiffel, best known for the Eiffel Tower. Climbing inside reveals the ingenious steel framework that supports Frédéric Auguste Bartholdi's iconic sculpture, offering a fascinating look at one of the great engineering achievements of the nineteenth century.

The 4-minute ride on the tram connecting Manhattan to Roosevelt Island offers sweeping views over the East River. Hop on at East 59th and 2nd Avenue (for a subway fare); when you exit on Roosevelt Island, turn right and walk along the promenade to the Franklin D. Roosevelt Four Freedoms Memorial Park designed by architect Louis Kahn. Framed by double rows of linden trees with sweeping river views of Manhattan and Brooklyn, it offers open lawns and an Imagination Playground for kids.

For younger children, start at the beloved Billy Johnson Playground, known locally as the Stone Slide Playground at East 68th Street and Fifth Avenue. Nearby are the Central Park Carousel, the model sailboats at Conservatory Water, and the ever-popular Alice in Wonderland sculpture. One of the joys of Central Park is discovering its many playgrounds, each with its own character, while open lawns invite impromptu games and picnics throughout the year.

Head for the Greek and Roman galleries, where monumental sculptures and soaring spaces immediately capture young imaginations. Kids’ favorites include the period rooms—particularly the New York Dutch Room from 1751 and the Ipswich Room from 1680—the Arms and Armor galleries, and the Musical Instruments collection. Before leaving, stop by the nearby 81st Street Studio, where hands-on activities encourage creativity and exploration.

Hours of enchantment await at this classic field museum—from the dioramas featuring life-size recreations of natural habitats around the world, to the 16-ft-diameter slice of a giant Sequoia tree (felled in 1891 but 1,400 years old); the blue whale suspended from the ceiling of the Hall of Ocean Life to the magnificent holdings of the Halls of Gems and Minerals. A place to let their imaginations light up and run wild.

On the first Saturday of every month, Diller Quaile School of Music hosts “rug concerts” open to all who purchase a ticket. Parents and children sit on a rug together during this unique New York experience led by professional musicians with real instruments and engaging for the entire family.

This French bookstore is located in Villa Albertine, the cultural arm of the French Consulate. The surprise and delight can be found upon entering the bookstore, which has a narrow staircase up to another level where you will find a room dedicated to wonderful books in French (and English too!), enjoyable by all ages. Look up and you will see a painted ceiling of constellations. It is a space beloved by children.

The Eero Saarinen-designed TWA Hotel at JFK is one of New York's great family outings. The restored 1962 terminal is a mid-century masterpiece, complete with vintage cars, a Lockheed Constellation cocktail lounge, and exhibits on the Jet Age. Children can explore the famous red-carpeted tunnels and original Saarinen interiors, while aviation enthusiasts will appreciate the architecture and runway views. Magical before a flight—or simply for an afternoon.