Correspondents' stories: once the cradle of the Arab Spring, Tunisia's now battling an Islamist insurgency and an huge influx of refugees from neighbouring Libya - Andrew Hosken has been investigating; Andreas Gebauer finds parallels between Israel's security barrier and the Berlin wall which he first saw as a young boy; Emilie Filou is in the Comoros Islands in the Indian Ocean meeting people desperate to start a new life in nearby French territory; Vincent Dowd's visiting a corner of south west Ireland he describes as paradise and Rob Crossan creates a stir among drinkers at the only pub in a remote town in Greenland.