This massive flat-topped pyramid will be built in Abu Dhabi — guess what it’ll be made of

Once complete, it will occupy a space larger than the Great Pyramids of Giza and rise taller than St. Paul's Cathedral. It's called the Mastaba — a 150 meter (500 feet) tall flat-topped pyramidal structure that was just approved for construction by Abu Dhabi officials. Designed by acclaimed artist Christo, the… » 11/29/12 11:20am 11/29/12 11:20am