Cold War

Pez Owen was joyriding in a Cessna airplane when she spotted one down below. A landmark that big would show up on any flight chart — but it wasn't logged. Then she spotted more X's in the distance.

As the world refocuses its attention on North Korea after the rogue nation's fourth nuclear test, in neighboring South Korea, day-to-day life has barely been affected.

American broadcaster Willis Conover was known around the world in places like Prague, Moscow and Warsaw, but not so much at home. For more than 40 years, he hosted a jazz show on the Voice of America.

Initially, the CIA was suspicious of Soviet aviation expert Adolf Tolkachev. But he earned the agency's trust — and provided blueprints, documents and plans that were crucial to the U.S.