Travel Photo of the Week: Guardian of Karnak Temple, Luxor, Egypt

Green ants build their grand nests out of leaves, which they pull and join together with silk. Amazingly, this silk is produced by their newborn larvae.

Magnificent Leaf Homes Woven by Australian Green Ants (2:50)

It's no secret that Charles IV, king of Bohemia, possessed the Spear of Destiny. But the way he brandished it in public reveals his savvy understanding of mythology and power.

Unlocking the Spear of Destiny's True Power (3:56)

Why saying cheese just didnt happen in the early days of photography.

Ask Smithsonian: Why Don’t People Smile in Old Photographs? (1:12)

In 1828, John Jacob Astor built a trading post on the Missouri River. Business was so profitable that it only took four decades for Astor to become America's first multimillionaire.

America's First Multimillionaire (2:49)