Grand Canyon and Biosphere on list of world's 50 must-see marvels

The Grand Canyon and the University of Arizona-operated Biosphere 2 [below, credit UA] are being called two of the world's "50 Must-See Natural and Man-made Marvels."

Life Books' "Wonders of the World" edition includes both man-made and natural wonders.

Other natural wonders on the list include the Galápagos Islands, the Serengeti in Africa, and the Rock of Gibraltar.

Man-made wonders include the Eiffel Tower, the Sydney Opera House, the National Stadium in Beijing, and Golden Gate Bridge. Other U.S.-based man-made wonders include the Empire State Building in New York City, Mount Rushmore in South Dakota. The Hubble Space Telescope and the International Space Station also made the list.