In the United States, six of those 15 natural wonders can be seen. The Grand Canyon National Park in Arizona, Kenai Fjords National Park in Alaska, Old Faithful Geyser at Yellowstone National Park in Wyoming, Joshua Tree National Park in California, Diamond Head State Monument in Honolulu, Hawaii, and Aurora borealis in the Arctic Circle.
Each natural wonder has it's own alluring factor to bring people to visit.
The Grand Canyon has a reported 5 million visitors each year. The gorge is one mile deep and up to 18 miles wide. While you are there, you can take a rafting trip. There are trips that range from half a day, to a full blown trip through the canyon lasting six to eight days for a motorized trip to 10 to 14 days for an oar powered trip.
Yellowstone National Park in Wyoming is the World's first national park. Yellowstone features the Old Faithful Geyser, but it is not the only geyser. There are more hot springs and geysers here than anywhere else on Earth.
Joshua Tree National Park in California is home to the giant yuccas called the Joshua tree, massive rock formations, fan palm oases, and seasonal gardens of cholla and ocotillo.
Diamond Head State Monument in Honolulu, Hawaii was created about 300,000 years ago when an eruption occurred causing ash and fine particles to fly into the air. As these materials settled, they cemented together into a rock called tuff, creating the crater, and which is visible from the trail in the park.
Kenai Fjords National Park in Alaska is known for the wildlife and glaciers. Approximately 27 land mammals and 10 marine mammals inhabit the area. This National Park is the smallest in Alaska yet is home of the Harding Icefield, an almost 714 square miles of ice up to a mile thick.
Aurora borealis in the Arctic Circle more commonly known as the Northern Lights. The amazing colors in the sky 'occur when highly charged electrons from the solar wind interact with elements in the earth's atmosphere.' Alaska and western Canada are the best places North America to view the Northern Lights.