Happy 126th birthday, Eiffel Tower!

Some 126 years ago, the Eiffel Tower opened its doors to the public for the first time. The enormous metallic structure is now a globally recognized, iconic piece of architecture.

But how much do you really know about the giant hunk of metal? Aside from the fact that it is incredibly tall, probably not much.

So today, on its 126th birthday, we thought it would be the perfect occasion to consider the interesting, and at times quirky, history of this amazing landmark:

Construction on the tower began on January 26, 1887, and took two years, two months, and five days to complete.

The tower was initially only supposed to stand for 20 years.

Painting the tower required 60 tons of paint (and still needs a fresh coat every seven years).

It is named after its designer, engineer Gustave Eiffel, who also designed the Statue of Liberty.

Many artists and architects in Paris had protested the construction of the tower, and even wrote a petition against it.

The Eiffel Tower shrinks. Seriously, it's been measured. In the winter it is approximately four to eight inches shorter.

Welcoming around 7 million visitors each year, it's the most visited monument in the world that have to pay for. (The Empire State Building only draws around 3.5 million visitors each year.)