Alice Roberts, Chris Howard, The Ayoub Sisters, Elizabeth Day

Broadcaster and biological anthropologist Alice Roberts reveals the secret behind the UK's fascination with castles.Chris Howard, one of the creators of David Attenborough's Wild Isles, discusses the trials and tribulations of filming the elusive beaver.Scottish-Egyptian musicians The Ayoub Sisters perform their revival of an old Arabic folk song; live in the studio.Author and Broadcaster Elizabeth Day shares her Inheritance Tracks.Presenters: Nikki Bedi and Peter Curran Producer: Ben Mitchell