Inside the Smithsonian
The Smithsonian National Museum of Natural History aims at increasing our knowledge of the planet we live on. With over 144 million different items in its collections, it's the world's largest of its kind. A few of these treasure are open to the public, but about 99 perfect of their objects remain locked away. In this behind-the-scenes look, director Dr. Kirk Johnson reveals the riches confined within the museum's walls.