20 June 2016
Photos from inside North Korea reveal how the ecology of the secretive Asian country is preventing the extinction of several once plentiful species of migratory birds.
Despite being closed to most foreigner visitors, North Korea may ironically be the saviour of one of the world's greatest international migration routes - the avian East Asian Australasian Flyway.
Fifty million birds, from cranes to song birds, journey along the Flyway twice a year. Eight million of those are shorebirds - or waders.
And for many thousands of those, North Korea's west coast - on the Yellow Sea - is their sole stop-off point.