(CNN) -- Here's some background information about the Eiffel Tower in Paris.
Facts: Almost 7 million people visit the Eiffel Tower annually.
Almost 250 million visitors have been to the tower since its construction.
The names of 72 French scientists are inscribed on the exterior of the first floor.
History: Construction: 1887 - 1889 (2 years, 2 months and 5 days).
1889 - The Eiffel Tower is 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 French 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 is the tallest building in the world.
1980-1985 - The structure is strengthened, and 1,343 tons of unnecessary materials are removed. New elevators going from the second floor to the top are added, as well as new panoramic restaurants. New lights (352 1,000-watt projectors) that light the tower from the structure interior are also added.
October 6, 2014 - The newly renovated first floor gallery is unveiled. The highlight is a new glass floor, which offers dramatic views of the 57-meter (187-foot) drop from the first level. The transparent walkway has already proved to be a hit with visitors.
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 7 cm. 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.
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.