Hu Jinnan's passion for running international marathons has taken him around the world. From New York City to Tokyo, he's crossed the finish line in a dozen such events.

So, naturally, the Pyongyang International Marathon was a challenge too good to miss.

"I was tempted by the mystery of the Democratic People's Republic of Korea, and I just love running marathons," says the 37-year-old, one of many Chinese athletes who have taken part since the race was opened to amateur overseas runners in 2014.