Duga Radar is the immense Soviet over-the-horizon radar array hidden in the forest near Chernobyl. Built to detect missile launches, it was once a secret military site and became known in the West as the "Russian Woodpecker" because of the tapping interference it caused on shortwave radio.
The scale is the reason to go: the steel lattice rises above the trees for hundreds of metres, turning Cold War paranoia into something physically overwhelming. Access depends on current exclusion-zone rules and guided itineraries, but it is one of the most memorable stops outside Pripyat itself.