Top 10 tallest structures

Don't look down! 125 years after French engineer Gustave Eiffel designed his eponymous tower, tourists still flock to Paris to climb it. Here's a look at our 10 favorite tall structures from around the world.

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  Ancient title holder

  The Cheops Pyramid of Giza in Egypt is the oldest structure on the international list of tallest buildings. Built around 2560 BC out of massive quarried stone, the pyramid houses the tomb of the Fourth Dynasty Egyptian pharaoh Khufu. For more than 3,800 years, it was the world's tallest structure.