The American Museum of Natural History, on the Upper West Side facing Central Park, is one of the largest and most visited natural history museums in the world, with 45 permanent exhibition halls. The dinosaur halls on the fourth floor are the best in America — the T. rex, mounted in an active hunting pose, the Apatosaurus skeleton, the hands-on fossil preparation lab — and the museum's collection of dinosaur fossils is genuinely unmatched.
The Rose Center for Earth and Space (the glass-enclosed sphere at the museum's northwest corner) holds the Hayden Planetarium, which has the best digital space show in New York. The hall of ocean life, dominated by a 94-foot blue whale model suspended from the ceiling, is another highlight. Admission is expensive; allow a full day. The pay-what-you-wish admission policy applies only to New York State residents.