Okay, the user is asking for something interesting about the Eiffel Tower. Let me think about what's unique or less commonly known.
First, I know the Eiffel Tower was built for the 1889 World's Fair, but maybe there's more. Oh, right, it was initially supposed to be a temporary structure. That's a good point. People might not know that.

Also, the height is interesting. It was the tallest building in the world for a long time. Maybe mention how it was a marvel of engineering with its iron framework. The construction details, like the number of rivets, could be a nice touch.

Another thing: the tower has three levels. The first two are open to the public, and the third is a private area. Maybe mention the view from the top. Also, the fact that it's a symbol of France and a major tourist attraction. But I should check if there are any other unique facts. Oh, the Eiffel Tower has a small post office where you can send postcards. That's a fun detail.

Wait, the user might also be interested in its role in history, like during World War II. But maybe that's too much. Focus on interesting facts rather than historical events. Also, the color changes for special occasions. The tower is painted every seven years, which is a maintenance fact.

I should structure the answer with a few key points: temporary structure, engineering feat, height, levels, post office, and color. Make sure it's concise and flows well. Avoid any incorrect info. Let me verify the number of rivets—yes, around 2.5 million. The height was 300 meters, then added the antenna. Okay, that's accurate. Alright, time to put it all together.

The Eiffel Tower, completed in 1889 for the Exposition Universelle (World's Fair) in Paris, was initially met with skepticism and even criticism from some of France’s leading artists and intellectuals, who called it a "useless and monstrous" iron structure. However, it has since become one of the most iconic symbols of France and a marvel of 19th-century engineering. Here’s a fun fact: the tower was designed to be temporary, with a 20-year lease, but it was saved from demolition due to its value as a radio and television transmission tower. Additionally, its iron framework contains 2.5 million rivets, and its height (330 meters including antennas) made it the tallest structure in the world for 41 years. Interestingly, the Eiffel Tower even has its own post office, where visitors can send postcards stamped with its image. 🇫🇷✨