Just inside the Chernobyl exclusion zone lies a must-see relic from the Soviet anti-ballistic missile early warning network. Now silent, this massive steel radar receiving station used to be responsible for detecting launches of intercontinental ballistic missiles (ICBMs) headed towards the Soviet Union.
Duga-1 (Not Duga-3 as some refer to it) was in commissioned in 1976 and operated until shortly after the Chernobyl Nuclear Power Plant explosion in 1986.
The Duga radar system was mighty, yielding upwards of 10,000,000 watts (10MW) of transmitting power. To put in perspective, it was so powerful that low-frequency radio signals were susceptible to interference from Duga no matter where you were on Earth. Electronics manufacturers in the 1970s and 1980s knew of this mysterious tapping or woodpecker sound and began engineering filters to block it. The amateur radio community and enthusiasts started a club called The Russian Woodpecker Hunting Club to target and block the tapping sound heard throughout the world. In the late 1980s with the cold war winding down and the eventual fall of the soviet union, the Duga radar ceased operation.