A train likely belonging to North Korean leader Kim Jong Un has been parked at his compound on the country’s east coast since last week, satellite imagery showed, amid speculation about his health that has been caused, in part, by a long period out of the public eye.

South Korean engineers rode a train into North Korea to inspect the hermit country’s railway network, in hopes of someday connecting the two nations.

North Korea's ruling family has long dreamed of a state-of-the-art rail system linking its major cities with each other and the wider world.