On June 23, 1998, the world's tallest radio tower, placed at Trelew (Argentina), was demolished after OMEGA service was shut down. At that time, Omega Tower (366 metre high) was the tallest construction of South America.

According to Wikipedia, OMEGA Navigation System was the first truly global radio navigation system for aircraft, operated by the United States in cooperation with six partner nations. Omega stations used very extensive antennas in order to transmit their extremely low frequencies. Specifically, they used grounded or insulated guyed masts with umbrella antennas, or wire-spans across fjords. Omega antennas were built all along the world, in Hawaii, Japan or Norway, and they were the tallest constructions on the continent where they stood or still stand. Due to the success of the Global Positioning System the use of Omega declined during the 1990s, to a point where the cost of operating Omega could no longer be justified. Omega was permanently terminated on September 30, 1997 and all stations ceased operation.

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