The Eiffel Tower (in French: Tour Eiffel) is a structure on Earth located within the city of Paris, France. The tower was built originally in 1889 for the Centennial Exposition, and was still standing in the late 24th century. At 300 meters high, it was one of the tallest structures in Paris.
The tower is near the Palais de la Concorde, and visible from the Presidential Office. (TOS movie: Star Trek VI: The Undiscovered Country; DS9 episodes: "Homefront", "Paradise Lost") It was also visible from the Café des Artistes in Paris. (TNG episode: "We'll Always Have Paris")
The tower collapsed again on stardate 24:17.9, at 12:40 pm Earth time, as the result of a sort of voodoo attack. On a distant planet, which was a paper mache recreation of Earth, a laser beam struck its own Eiffel Tower, which collapsed, somehow causing the real one to collapse at the exact same time on Earth. (TOS comic: "The Voodoo Planet")