"Heart of France" is a metaphor that usually refers to Paris as a whole, as the main city of France and the cultural center of the country.
The Eiffel Tower, one of the most famous landmarks in Paris, is often used as a symbol of France and its capital. It was built in 1889 and has become a symbol of French national pride and technological progress.
The Eiffel Tower was created for the 1889 World's Fair, which celebrated the centenary of the French Revolution and was organized to showcase the achievements of French science and technology. The Eiffel Tower became the tallest building in the world at that time and continues to be one of the most recognizable and visited places in the world.
Although the Eiffel Tower is an important symbol of Paris and France, it is not the only one. There are many other iconic places in Paris, such as Notre Dame de Paris, the Louvre, Chance Elise, Montmartre and others, which together form the overall image of the city.