In the summer of 1987, the American swimmer Lynne Cox braved the frigid waters of the Bering Strait to swim from the United States to the Soviet Union. Twenty-five years on, now aged 55, she recalls how her actions in the waning days of the Cold War eased international tensions.

"I wanted to open the border so we could become friends," says Cox. "The difficulty was that nobody believed it could happen."

Her route between Little Diomede Island, in the US state of Alaska, and Big Diomede Island, in the Soviet Union, was just 4.3km (2.7 miles) but it crossed the maritime border of two countries still locked in Cold War opposition, and the water was cold, very cold.