NATIONAL MUSEUM OF NATURAL HISTORY
THE SMITHSONIAN INSTITUTION
Tenth Street and Constitution Avenue
Washington, D.C. 20560
This is one of the most outstanding dinosaur exhibits in the United States -- no surprise since it's part of the Smithsonian Institution! Here you'll see an awesome Triceratops model, as well as Tyrannosaurus rex, Diplodocus, Stegosaurus, and many more. There are also more great exhibits of ancient mammals and marine life, as well as a working paleontological lab.
Museum admission is free, making it a super deal for dino lovers. Plan to spend plenty of time here -- it's well worth it. The gift shop is also particularly great for souvenirs. You'll spend plenty of time there as well! There is a restaurant in the Museum, but it gets very crowded during peak tourist season. Tip: Plan to vist restaurants off the Mall area for shorter lines and lower prices.