The Eiffel Tower is one of the world's most iconic monuments, with millions of visitors coming to marvel at it every year. You may have already known that it was built in 1889 and is re-painted every 7 years, but there are plenty of little-known facts about the tower that you may not know.

Check out these fascinating facts about the Eiffel Tower, and make sure to see the real thing for yourself if you haven’t already.

1. The Building of the Tower

The Eiffel Tower was designed by the French engineer and bridge builder Alexandre Gustave Eiffel to celebrate the 100th year anniversary of the French Revolution. The two years, two months and five days it took to build it is considered both a technical and architectural achievement.

2. The Visitors

Since it opened in 1889, almost 250 million visitors have come to see the tower. TToday, it welcomes almost 7 million visitors a year, 75 percent of whom are foreigners, making it the most visited monument that you have to pay for in the world. A study done by Client Watchdog asked 5,000 visitors about who they visit the tower with, and reported that 3 percent said they visit alone, 18.1 percent visit with friends, and 30 percent said they visit with an organized group. The most popular response was visiting with family, which was made up of 48.9 percent of visitors.

3. The Sparkling Tower

The Eiffel Tower has 20,000 lightbulbs, 5,000 per side, that sparkle for five minutes on the hour, every hour, from nightfall to 1AM. What might surprise some is that it is illegal to take a photograph of the tower at night because the light display is considered artwork and therefore protected under copyright law.  Snap off a picture and you can be fined.

4. The Capture of Mata Hari

The French military used the Eiffel Tower’s wireless station to intercept enemy messages from Berlin during World War I. In 1917, the radio station above the tower intercepted a coded message between Germany and Spain that included information about ‘Operative H-21’ otherwise known as the Dutch-born exotic dancer Margaretha Geertruida Zelle  MacLeod, whose stage name was Mata Hari who was spying for the Germans.  Based on this message, the French were able to arrest, convict and execute Mata Hari for espionage.

5. Dangerous and Deadly Aerial Feats at the Tower

For decades, daredevils have used the tower to stage crazy stunts, using everything from parachutes to bungee cords. In 1912, French tailor Franz Reichelt attempted to fly from the first floor with a spring-loaded parachute suit, but crashed 187 feet to the ground instead. Fourteen years later, aviator Leon Collot attempted to fly his plane under the tower but was killed when it became entangled in the aerial from the wireless station, and crashed in a ball of flame.

6. Suicides aren’t Totally Unheard of, But They’re Not That Common Either

There have only been 349 successful suicides since the tower first opened in 1889, according to the Societe de la Tour Eiffel. Some were jumpers, while others were people hanging themselves from the beam, and those who did attempt to jump from the first level don’t always die.