National Museum of Natural History

The National Museum of Natural History on the National Mall is the Smithsonian's flagship natural history museum, open since 1910. Behind its domed neoclassical facade sit roughly 145 million specimens and artefacts, one of the deepest collections on Earth. Henry the African bush elephant has greeted visitors in the rotunda for decades; the Hope Diamond room displays a 45.52-carat blue stone trailing rumors of a curse; and the David H. Koch Hall of Fossils, reopened in 2019, stages the Nation's T. rex mid-attack on a Triceratops. A live butterfly pavilion, a deep-sea ocean hall and a vault of meteorites round out the floors. Admission is free like all Smithsonian museums, which means busy weekends bring real queues at the most famous halls.