Eiffel Tower (photography by photoserge.com)

1889: During the evening of the tower’s inauguration, 10,000 gas street lamps adorned the steeple and platforms. Two projectors on the tower top illuminated the other Parisian monuments below. The blue, white and red beacon lights were considered the most powerful in the world.

1900: Electricity arrives at the Eiffel Tower, as 3,200 lamps spotlight its framework and decorative arches.

1925-1936: André Citroën adds the first decorative lighting display to the tower. As an ad campaign, the name Citroën is sculpted from 250,000 colored lamps, which adorns three sides of the tower and is visible 30 kilometers away.

1985, New Year’s Eve: Inauguration of a new lighting system, the final phase of a comprehensive restoration program, initiated by the city of Paris in 1980. The gold-toned, twinkling lighting system comprises 352 sodium lamps mounted on the inside of the tower.

2000, New Year’s Day: The Eiffel Tower is adorned in festive lighting composed of 20,000 spots and a beacon projector on the tower top.

2001, New Year’s Day: For the New Year, blue filters are placed over the lamps, allowing the sparkling lights to take on blue sapphire tones.

2001, July 14: The glittering light system is dismantled.

2003, June 21: The Eiffel Tower is once again covered in diamond-sparkling lights that are displayed for five minutes, every hour on the hour, from dusk until 2 a.m. (1 a.m. in winter).

The two light beams at the top of the tower can be seen up to 80km away. The beacon is composed of four marine-type, motorized projectors, operated by automatically piloted computer programs. Their rotation sweep is 90°, so they are synchronized to form a double beam in a cross that pivots around 360°. The 6,000-watt lamps, which last for approximately 1200 hours, are cooled to prevent overheating and also heated when the temperatures drop below zero centigrade and the lights are off.