Canadian couple Justin and Anna Williams have traveled to over 100 countries.
Of all the places they've been, the Democratic People's Republic of Korea has been the most memorable by far.
They were shocked to see how heavily tourists are supervised there, as well as how little some North Koreans knew about outside cultures.
"It’s like traveling to a different world," Justin told Business Insider.
They arranged their trip in 2012 through a travel operator with links to the state-owned Korean International Tourist Company.
We've put together a collection of images that show what the experience was like for them, from the tight restrictions they faced to the fascinating sights they saw.