The Eiffel Tower, today the most iconic building in all of France and the symbol of Paris, opened on March 31, 1889. The tower was built by architect Gustave Eiffel. It took two years to build and was the largest man made structure in the world at that time. Remarkably, the Eiffel Tower was not originally meant to be a permanent structure. It was built for an international exhibition held in France to honor the 100th anniversary of the French Revolution. Many people who lived in Paris at the time were not fans of the tower, considering it a structurally unsound eyesore. It was supposed to be demolished after two decades standing, but by then it had taken on another important purpose as a radio antenna, so it remained in place.