When battle is done, the exhausted bighorns make their way to the canyon rim. But they must be wary, as the canyon is also home to large predators, and a fierce mountain lion is on the prowl. The awe-inspiring vastness of the Grand Canyon attracts numerous tourists, but many will go no further than the lookout points due to the challenging terrain.

There are few places on Earth as breathtakingly spectacular as the Grand Canyon. One of the last great American wildernesses to be charted and explored, this mile deep rift in the landscape has been designated a national park. Among the wildlife to dwell in this remote and often harsh environment are the sure-footed, hard-headed, and sometimes quarrelsome bighorn sheep.

The University of Cambridge is one of England's greatest universities. There's no main campus – instead, the university's many colleges are scattered throughout the charming town center. Many colleges welcome the public to browse around.

Most Americans don't realize how Columbus Day came to be a national holiday, but it actually doesn't have that much to do with Christopher Columbus, and we might even recognize a connection to present-day events. To recall something Mark Twain once supposedly said, "History doesn't repeat itself, but it often rhymes."

Columbus Day has always been a controversial holiday in the United States. In this video, Sigrid goes back in time to get some historical background, which sheds a new light on its significance.

The honey badger is described as the most fearless animal on the planet. Although barely a foot tall, they have a reputation for attacking just about anything—from venomous snakes to full-grown lions. And they are not exactly meant for captivity: Stoffel the honey badger escapes from his enclosure regularly using anything from balls of mud to a rake.

Are you interested in aviation? Here's the first chapter of a documentary about the invention of the airplane entitled Kitty Hawk: The Wright Brothers' Journey of Invention.