This gigantic antenna system called Duga-3 is located near Prypiat in the Chernobyl area.
Abandoned, Radar Sites
It was built in the 70's as an early missile detection system (over-the-horizon radar system). It was also called the Steel Yard hence its distinctive appearance. The antenna was deactivated in 1989.
Links: www.artificialowl.net, en.wikipedia.org