The Eiffel Tower's searchlights are so powerful they can be seen from 50 miles away.

The current lighting system on the Eiffel Tower was inaugurated on December 31, 1999, to mark the transition into the year 2000. It consists of four motorized 'Marine' type searchlights equipped with 6,000-watt xenon lamps. These lamps are known for their high intensity and ability to produce a crisp, white light that mimics natural sunlight, making them visible from a distance of up to 80 kilometers or approximately 50 miles.The searchlights are synchronized by a computer to rotate in a circular motion, creating a cross-shaped beam that sweeps over the Parisian sky. Each lamp has a lifespan of around 1,200 hours and requires significant power to maintain its brightness. The choice of xenon technology is deliberate because it provides the necessary focus and reach to penetrate the atmospheric haze often found over large urban areas.Historically, Gustave Eiffel designed the tower with scientific utility in mind to save it from being demolished after its 20-year permit expired. In the early 20th century, specifically during the 1900 Universal Exhibition, the tower featured a powerful lighthouse that could be seen for miles. This served both as a navigational aid and a method for optical telegraphy, allowing the military to send signals before wireless radio technology became the standard for long-distance communication.