- [Narrator] The Eiffel Tower is an engineering icon that changed the face of the modern world.

Here are five things you may not know about it.

The Eiffel Tower was used as a one-of-a-kind antenna during World War I.

In March, 1918, it intercepted a coded German radiogram.

After it was deciphered, the French successfully avoided German attack turning the tides of the War.

The tower has been painted 19 times since its construction to protect it from corrosion, an average of once every seven years from one painting to the next, the tower's colors have changed several times.

At the time of the World's Fair, it was red, but recently the tower has been repainted the same color as in 1907.

It took 60 metric tons of paint to complete the tower's latest paint job.

It was originally built as a monument for the 1889 World's Fair in Paris.

At the time, it was the tallest structure in the world standing at 1,000 feet tall, more than four times taller than the Notre Dame Cathedral, more than double the height of the Great Pyramid of Giza, and almost twice as tall as the Washington Monument.

The concept for the Eiffel Tower didn't come from Gustave Eiffel, the engineer for whom the tower is named.

Two of his engineers drew the first few sketches, but Eiffel didn't think the design was attractive.

A few weeks later, another architect added decorative arcs to the original sketch, as well as platforms for public use.

Eiffel finally became excited by the Project.

Eiffel built a one-of-a-kind elevator.

In this space, located right below one of the tower's pillars.

Eiffel built an elevator based on the same technology he used to level the tower, hydraulic pressure.

(slow relaxing music)