If you are scheduled to take a Grand Canyon tour, you probably can't wait to get out there and see this wonder for yourself. But how much do you really know about the Grand Canyon, aside from the fact that it is a huge hole in the ground? Learning a bit more before your tour will make the experience even more interesting. To that end, here are five awesome facts about the Grand Canyon.

It's one of the seven wonders of the world.

The list of "seven wonders of the world" has changed a bit over the years, but the Grand Canyon has long been in the list. It's the only natural wonder in the U.S. to have made the list. Other natural wonders include Victoria Falls in Zimbabwe, the Great Barrier Reef in Australia, and Mount Everest in Nepal.

It's 277 miles long.

It would take you 4 1/2 hours to drive the length of the Grand Canyon if you were traveling at a modest 60 miles per hour! That's one long canyon. For this reason, most tours of the Grand Canyon won't show you the entire thing. The easiest way to see it is actually to go up in a helicopter or airplane and look down on the world beneath you.

The Colorado River runs through it.

If you look down into the canyon, you will see the river. Scientists think that this river actually carved the canyon as it flowed through the area for thousands and thousands of years. The canyon is growing ever deeper as the Colorado River continues to wear it away. The river empties into the Gulf of California.

It became a national park in 1919. 

President Woodrow Wilson passed a bill to make the Grand Canyon and surrounding area a national park in 1919. It officially became a national park on February 26th of that year, and if you visit the canyon on that day, you will find various celebrations of its birthday. At the time, it was only the 17th national park added to the register. 

You need a permit to camp there.

You might hear of backpackers and explorers just pitching a tent and spending time in the wilderness, but as this turns out, the practice is illegal. Anyone staying overnight in the park needs a permit from the park office. This is for your own protection in case something happens to you.