The dozen sites related to Japan's persecution of "Hidden Christians" have been awarded World Heritage status largely due to the fact that they show how the believers protected their faith at all costs, experts say.

UNESCO's World Heritage Committee recognized that the "Hidden Christian Sites in the Nagasaki Region" — 12 locations that include small villages where people secretly practiced Christianity — "bear unique testimony to a distinctive religious tradition."

A UNESCO advisory board offered its own suggested sites to the government, which led to their being selected as World Heritage sites on June 30.