(CNN) -- Here's a look at what you need to know about the Eiffel Tower in Paris.
History: Construction: 1887 - 1889 (2 years, 2 months and 5 days).
1889 - The Eiffel Tower was built for the Universal Exposition celebrating the centenary of the French Revolution and as a tribute to French industry and science.
March 31, 1889 - Opening day, the flag of France is placed atop the third level by Eiffel to the sound of a 21 canon salute.
1930 - Until the construction of the Chrysler Building in New York by William Van Allen, the Eiffel Tower was the tallest building in the world.
Construction: Contractor: Gustave Eiffel & Cie
Engineers: Maurice Koechlin & Emile Nouguier
Architect: Stephen Sauvestre
50 engineers and designers produced 5,300 "blueprints."
100 ironworkers produced the 18,038 individual parts to be assembled.
121 men worked on the construction site.
Characteristics: Metal framework weight: 7,300 tons
Total weight: 10,100 tons
The force of the wind causes the top of the Tower to sway 6 to 7cm. Heat also causes the tower top to move, with a curve of movement measuring 18cm (7.09 inches).
Height: - 1889 (height with flag): 312.27m (1024.5 ft) - 1991 (height with antenna): 317.96m (1043.18 ft) - 1994 (height with antenna): 318.70m (1045.60 ft) - 2000 (height with antenna): 324.00m (1062.99 ft)
The Tower is repainted every 7 years, necessitating 60 metric tons of paint.
There are 1665 steps to the top of the tower.
1980-1985 - The structure was strengthened, while 1,343 tons of unnecessary materials were removed. New elevators going from the second floor to the top were added, as were new panoramic restaurants. New lights (352 1,000-watt projectors) that light the tower from the structure interior were also added.
Other Facts: Almost 7 million people visit the Eiffel Tower annually.
Almost 250 million visitors have been to the tower since its construction.
The first floor gallery is 57m (187ft) above Paris and is undergoing a renovation expected to take more than two years.
The names of 72 French scientists are inscribed on the exterior of the first floor.
Visitors have the option of taking the elevators or walking up the stairs to the second floor. The third level is only accessible by elevator.