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

A hammerhead shark locates a stingray hiding beneath the ocean floor. Unnerved, the stingray makes a dash for freedom but is it too late?

Hammerhead vs. Stingray (2:25)

Prepare to be amazed.

Ask Smithsonian: What’s a Stone Baby? (1:07)

Free from their mother's care, five young lions must fend for, and feed, themselves. Their first challenge: a giant giraffe who refuses to be caught.

Incredible: Five Lions Take Down a Giraffe (2:49)

One highly influential ancient Middle Eastern civilization established some of the essential systems we still use today. Think you know which it is?

Who Decided to Put 60 Seconds in a Minute? (2:33)