About 50 million people come to the United States on vacation each year. A lot of them head for popular tourist destinations, such as New York City, Las Vegas, New Orleans, or one of the big entertainment theme parks, such as Disneyland in California.

But why? Why go there, when there are so many lesser-known, but appealing, places to visit?

Arkansas, for instance, where you can tour America's only active diamond mine. And while you're into wealth, drive up to Fort Knox in Kentucky, a federal facility where more than six billion dollars' worth of gold bullion is stored deep beneath the earth. OK, so there's no chance whatsoever that the soldiers will let you even peek at it. But you can say you were there, and get a Fort Knox bumper sticker!

Or head for Minnesota, home of the Mall of America -- the nation's largest shopping arcade. There, you can literally shop till you drop. If you spend just ten minutes in each of the stores, it will take you four days to visit them all.

To the west, North Dakota, which is still cold -- cold! -- this time of year, is always looking for visitors. Bring your compass or global positioning device to Rigby, North Dakota, the geographical center of all of North America. You'll be in the middle of it all!

Then cruise down to South Dakota -- anywhere in South Dakota -- and relax, because South Dakota is the only U.S. state that's never had an earthquake.

Before heading home, you'll want to warm up a bit but still do some exploring. We'd recommend Jacksonville, Florida. It's America's largest city: the most spread-out. At two thousand square kilometers, it's the size of Cyprus, and larger than lots of other whole countries. So while you're up at the Mall of America, buy some good walking shoes.