Watch Series: Secret Knowledge Released in (2013) - Season 1 produced by UK, The TV Series categorized in Documentary, and content rating 30min with duration 30 min broadcasted as these networks BBC Four, Streamed at Putlocker & directed by Katy Homan, John Hodgson, Sharon Adam. In a series of authored films, some of our most engaging experts reveal their favourite hidden objects, forgotten places and artistic passions. - Season 1